Antimicrobial composition

Abstract

Provided here are antimicrobial compositions comprising an alkylene glycol ester and at least one antimicrobial compound, wherein suitably said alkylene glycol ester and said antimicrobial compound are present in the antimicrobial composition in beneficial weight ratios. Also provided are methods for increasing the efficacy of antimicrobial compounds and methods for reducing the minimum amount of antimicrobial compound needed for effective preservation activity in end-use formulations.

Description

[0001] Applicant: Arch UK Biocides Limited

[0002] Antimicrobial composition

[0003] Technical Field

[0004] The present invention relates to antimicrobial compositions comprising an alkylene glycol ester and at least one antimicrobial compound, wherein suitably said alkylene glycol ester and said antimicrobial compound are present in the antimicrobial composition in weight ratios for providing synergism. In addition, the present invention relates to a method for inhibiting microbial growth in an end-user formulation (e.g. personal care or home care product) comprising said antimicrobial compositions and to end-user formulations comprising said antimicrobial compositions.

[0005] Technological Background

[0006] Microbial contamination of personal care products such as cosmetics and home care products and other similar products is a matter of great importance to the industry such as personal care industry. Microbial contamination can become a major cause of product losses of end-use formulations and can cause significant economic loss. Further, contamination of cosmetics and home care products can result in their being converted into products that are hazardous for consumers. Certain antimicrobial compounds and antimicrobial compositions for protecting against microbial attack either from bacterial or fungal sources are known in the art. These antimicrobial compounds have a wide variety of applications in fields such as personal care products, home care products, and health and hygiene products.

[0007] There are continued regulatory pressures to reduce the amount of the antimicrobial compound(s) in end-use formulations. Similarly, in the field of formulations such as personal care formulations there are ongoing regulatory pressures to reduce the amount of the active ingredient in said formulations. Additionally, there are continued regulatory pressures to stop using certain conventional antimicrobial compound(s) or to reduce the amount of certain conventional antimicrobial compound(s) in end-use formulations.

[0008] Accordingly, a need exists for antimicrobial compositions that contain less active ingredient or antimicrobial compounds while maintaining acceptable levels of overall antimicrobial efficacy. Summary of the invention

[0009] The above needs are met by the compositions and methods of the present invention. Accordingly, the present invention provides a (suitably synergistic) mixture of at least one antimicrobial compound with an alkylene glycol ester, which can be used in various formulations, including personal care and home care formulations. The inventors surprisingly found that the antimicrobial composition allows to apply little amount of active ingredients when alkylene glycol ester and the at least one antimicrobial compound are both present while still producing the desired antimicrobial efficacy.

[0010] In a first aspect, the present invention relates to an antimicrobial composition comprising an alkylene glycol ester and at least one antimicrobial compound selected from the group consisting of citric acid and salts thereof, salicylic acid and salts thereof, gluconolactone, levulinic acid and salts thereof, ethyl levulinate, butyl levulinate, ethylhexyl glycerin, ethylene glycol, 1 ,3-propanediol, 1 ,3- butanediol, 2,3-butanediol, 1 ,2-pentanediol, 1 ,2-hexanediol, caprylyl glycol, ethyl lactate, butyl lactate, climbazole, 1 ,2-decylene glycol, 4-hydroxyacetophenone, caprylhydroxamic acid and salts thereof, glyceryl caprylate, chlorphenesin, 5-Chloro-2-(2,4-dichlorophenoxy)phenol (also known as triclosan), methylheptylglycerin, polyglyeryl- 2 or 3 or 4 or 6 or 10 -caprylate, polyglyeryl- 2 or 3 or 4 or 6 or 10 -caprate / caprylate, azelaic acid, Vitamin C, zinc oxide, zinc citrate, zinc Pyrrolidone Carboxylic Acid (zinc PCA), zinc glycinate, zinc oxide, niacinamide, hyaluronic acid, 2-methyl 5- cyclohexylpentanol, Aluminium sulphate, Aluminium zirconium, Aluminum chloride, aluminium chlorhydrate, other aluminium salts, benzoyl peroxide, glycolic acid, phenethyl alcohol, 3- phenylpropan-1-ol, anisic acid and salts thereof, 1 ,2-heptanediol, caprylyl glyceryl ether, capryloyl glycine, tetrasodium glutamate diacetate, trisodium dicarboxymethyl alaninate, and phytic acid and salts thereof, wherein said alkylene glycol ester and said antimicrobial compound are present in a weight ratio of about 1 :1000 to about 2500:1 .

[0011] In a second aspect, the present invention relates to an antimicrobial composition comprising an alkylene glycol ester and at least one antimicrobial compound selected from the group consisting of citric acid and salts thereof, salicylic acid and salts thereof, gluconolactone, levulinic acid and salts thereof, ethyl levulinate, butyl levulinate, ethylhexyl glycerin, ethylene glycol, 1 ,3-propanediol, 1 ,3- butanediol, 2,3-butanediol, 1 ,2-pentanediol, 1 ,2-hexanediol, caprylyl glycol, ethyl lactate, butyl lactate, climbazole, 1 ,2-decylene glycol, 4-hydroxyacetophenone, caprylhydroxamic acid and salts thereof, glyceryl caprylate, chlorphenesin, triclosan, methylheptylglycerin, polyglyeryl- 2 or 3 or 4 or 6 or 10 -caprylate, polyglyeryl- 2 or 3 or 4 or 6 or 10 -caprate / caprylate, azelaic acid, nonanoic acid, Vitamin C, zinc oxide, zinc citrate, zinc Pyrrolidone Carboxylic Acid (zinc PCA), zinc glycinate, zinc oxide, niacinamide, hyaluronic acid, 2-methyl-5-cyclohexylpentanol, Aluminium sulphate, Aluminium zirconium, Aluminum chloride, aluminium chlorhydrate, other aluminium salts, benzoyl peroxide, glycolic acid, phenethyl alcohol, 3-phenylpropan-1-ol, anisic acid and salts thereof, 1 ,2-heptanediol, caprylyl glyceryl ether, capryloyl glycine, tetrasodium glutamate diacetate, trisodium dicarboxymethyl alaninate, and phytic acid and salts thereof, wherein said alkylene glycol ester and said antimicrobial compound are present in a synergistically effective amount.

[0012] In a third aspect, the invention relates to an end-use formulation, preferably a home care or personal care product, comprising an antimicrobial composition according to the invention.

[0013] In a fourth aspect, the present invention relates to a method for inhibiting microbial growth in a home care, a personal care product, or an aqueous raw material for addition into a home care or personal care product comprising the step of adding the antimicrobial composition according to the invention to said home care or personal care product or aqueous raw material.

[0014] In a fifth aspect, the invention relates to a method for preventing an end-use formulation, preferably a home care or personal care product, from spoilage by microorganisms, the method comprising adding the antimicrobial composition according to the invention to the end-use formulation, preferably the home care or personal care product.

[0015] In a sixth aspect, the invention relates to the use of the antimicrobial composition according to the invention for increasing the efficacy against microorganisms compared to an equal amount of the at least one antimicrobial compound without said alkylene glycol ester, preferably wherein the increased efficacy is identified by a synergy index value of less than 1 .

[0016] In a seventh aspect, the invention relates to method for increasing the efficacy of an antimicrobial compound against microorganisms in an end-use formulation, said method comprising providing an end-use formulation and at least one antimicrobial compound, adding an effective amount of an alkylene glycol ester to the least one antimicrobial compound and end-use formulation to increase the efficacy of the at least one antimicrobial compound in the end-use formulation, as compared to an equal amount of said antimicrobial compound without said alkylene glycol ester in the end-use formulation, wherein the at least one antimicrobial is selected from the group consisting of citric acid and salts thereof, salicylic acid and salts thereof, gluconolactone, levulinic acid and salts thereof, ethyl levulinate, butyl levulinate, ethylhexyl glycerin, ethylene glycol, 1 ,3-propanediol, 1 ,3- butanediol, 2,3-butanediol, 1 ,2-pentanediol, 1 ,2-hexanediol, caprylyl glycol, ethyl lactate, butyl lactate, climbazole, 1 ,2-decylene glycol, 4-hydroxyacetophenone, caprylhydroxamic acid and salts thereof, glyceryl caprylate, chlorphenesin, triclosan, methylheptylglycerin, polyglyeryl- 2 or 3 or 4 or 6 or 10 -caprylate, polyglyeryl- 2 or 3 or 4 or 6 or 10 -caprate / caprylate, azelaic acid, Vitamin C, zinc oxide, zinc citrate, zinc Pyrrolidone Carboxylic Acid (zinc PCA), zinc glycinate, zinc oxide, niacinamide, hyaluronic acid, 2-methyl-5-cyclohexylpentanol, Aluminium sulphate, Aluminium zirconium, Aluminum chloride, aluminium chlorhydrate, other aluminium salts, benzoyl peroxide, glycolic acid, phenethyl alcohol, 3-phenylpropan-1-ol, anisic acid and salts thereof, 1 ,2-heptanediol, caprylyl glyceryl ether, capryloyl glycine, tetrasodium glutamate diacetate, trisodium dicarboxymethyl alaninate, nonanoic acid, and phytic acid and salts thereof; and wherein said alkylene glycol ester is derived from (a) an alkylene glycol, and (b) a fatty acid having from about 6 to 14 carbon atoms.

[0017] Detailed description of the invention

[0018] In the following, the invention will be explained in more detail.

[0019] Definitions

[0020] In order for the present invention to be readily understood, several definitions of terms used in the course of the invention are set forth below.

[0021] In general, the present invention is directed to an antimicrobial composition. As used herein, the term “antimicrobial compound” means a biocidal agent or biocidal composition which is intended to be blended with into an end-use formulation, such as personal care formulations, home care formulations, and health and hygiene products, to prevent microorganisms from destroying the enduse formulation or making the end-use formulation unusable for the particular purpose for which the end-use formulation was developed.

[0022] It has now been surprisingly found that adding an amount of an alkylene glycol ester to antimicrobial compound(s) intended for an end-use formulation can provide an effective antimicrobial end-use formulation with a synergistic interaction between the antimicrobial compound(s) and the alkylene glycol ester. As used herein, a “synergistic interaction” refers to the fact that the antimicrobial compound(s), when combined with the alkylene glycol ester has a total antimicrobial / antifungal effect that is greater than the antimicrobial / antifungal properties of the antimicrobial compound(s) alone, or the alkylene glycol ester alone. In other words, the antimicrobial compound(s) of the present invention operates synergistically with the alkylene glycol ester so as to have greater antimicrobial / antifungal activity in the presence of each against certain microorganisms than in comparison to the antimicrobial activity of the antimicrobial compound(s) alone or the antimicrobial activity of the alkylene glycol ester alone at the same concentrations. Due to the synergistic effect, the amount of the antimicrobial compound(s) present in the antimicrobial composition can be reduced while still producing the desired efficacy. This effect is also known as “potentiation” of the antimicrobial compound(s) in the antimicrobial composition. This potentiation of the antimicrobial compound(s) is also referred to herein as a “synergistic effect” between the antimicrobial compound(s) and the alkylene glycol ester(s) for boosting the efficacy of the antimicrobial compound(s).

[0023] Further, use of the antimicrobial composition disclosed herein provides numerous technical advantages and benefits. For example, the antimicrobial composition(s) disclosed herein can maintain antibacterial and / or antifungal activity at various pH levels. Furthermore, the antimicrobial composition(s) disclosed herein generally remain stable during changes in temperature and changes encountered during manufacturing, packaging, shipping, and storage of the endformulation in which the antimicrobial composition may be included. Further, the antimicrobial composition(s) disclosed herein are physically and chemically compatible with ingredients present in various end-use formulations. Lastly, as described further herein, the antimicrobial composition(s) of the present invention may contain lesser amounts of an antimicrobial compound yet still provide antimicrobial efficacy consistent with industry standards.

[0024] The term “alkyl” as used herein denotes in each case a straight-chain or branched saturated hydrocarbon group having usually from 1 to 8 carbon atoms, preferably 1 to 6 or 1 to 4 carbon atoms, more preferably 1 to 3 or 1 to 2 or 1 carbon atoms. Examples of an alkyl group are methyl, ethyl, n-propyl, iso-propyl, n-butyl, 2-butyl, iso-butyl, tert-butyl, n-pentyl, 1 -methylbutyl, 2- methylbutyl, 3-methyl-butyl, 2,2-dimethylpropyl, 1 -ethylpropyl, n-hexyl, 1 ,1 -dimethylpropyl, 1 ,2- dimethylpropyl, 1 -methylpentyl, 2-methylpentyl, 3-methylpentyl, 4-methylpentyl, 1 ,1 -dimethylbutyl, 1 ,2-dimethyl-butyl, 1 ,3-dimethylbutyl, 2,2-dimethylbutyl, 2,3-dimethylbutyl, 3,3-dimethylbutyl, 1- ethylbutyl, 2-ethylbutyl, 1 ,1 ,2-trimethylpropyl, 1 ,2,2-trimethylpropyl, 1-ethyl-1 -methylpropyl, 1-ethyl- 2-methylpropyl, and the like.

[0025] The term “alkenyl” as used herein denotes in each case a straight-chain or branched hydrocarbon group having usually from 2 to 18 carbon atoms, frequently from 2 to 8 or 2 to 6 carbon atoms, with one or more C=C double bonds. The alkenyl moieties, where appropriate, can be of either the (E)- or (Z)-configuration. The term “alkynyl” as used herein denotes in each case a straight-chain or branched hydrocarbon group having usually from 2 to 18 carbon atoms, frequently from 2 to 8, 2 to 6, or 2 to 4 carbon atoms, with one or more C=C triple bonds.

[0026] The term “cycloalkyl” as used herein refers to a saturated bi- or monocyclic hydrocarbon that has - in general and if not defined otherwise in the specification - a single point of attachment to the remainder of the molecule, with 5, 6, 7, 8, 9, 10, 11 , 12, 13, 14, 15, 16, 17, or 18 ring carbon atoms. C3-8-cycloalkyl groups may be unsubstituted or substituted with - unless specified differently elsewhere in this specification - 1 , 2 or 3 substituents that may be the same of different and are - unless specified differently elsewhere in this specification - selected from the group comprising C1- 6-alkyl, C1-6-alkoxy, halogen, hydroxy, unsubstituted or mono- or di-substituted amino. Exemplary cycloalkyl groups are cyclopentyl, cyclohexyl, and cycloheptyl.

[0027] The term “aryl” (either alone or as part of a larger group, such as e.g. aryloxy) as used herein refers to aromatic ring systems (i.e. fulfilling the Huckel rule - having (4n+ir2) electrons, with n being 0 or an integer of preferably 1 to 3) which can be in mono-, bi- or tricyclic form. Examples of such rings include phenyl, naphthyl, or indenyl. Preferred aryl groups are phenyl and naphthyl, phenyl being most preferred. A suitable example for aryloxy rings includes phenoxy.

[0028] The term “alkoxy” as used herein denotes in each case alkyl substituents as defined above that are connected to another structural moiety via an oxygen atom (-O-). Exemplary alkoxy groups are methoxy, trifluoromethoxy, ethoxy, 2,2,2-trifluoroethoxy, n-propoxy, iso-propoxy, n-butoxy, secbutoxy, tert-butoxy, n-pentoxy.

[0029] The organic moieties mentioned in the above definitions of the variables are - like the term halogen - collective terms for individual listings of the individual group members. The prefix Cn-Cm (as well as Cn to Cm or Cn-m) indicates in each case the possible number of carbon atoms in the group.

[0030] The term “carbonyl” as used herein denotes a carbonyl moiety, also known as “C(O)” or “C=O”.

[0031] The term “halogen” denotes in each case fluorine, bromine, chlorine, or iodine.

[0032] As used herein, the term “comprising” is to be construed as encompassing both “including” and “consisting of’, both meanings being specifically intended, and hence individually disclosed, embodiments according to the present invention. The compositions of the present invention can include (comprise), consist essentially of, or consist of, the components of the present invention as well as other ingredients described herein. As used herein, “consisting essentially of’ means that the composition or component may include additional ingredients, but only if the additional ingredients do not materially alter the basic and novel characteristics of the claimed composition or methods.

[0033] As used herein, the articles “a” and “an” preceding an element or component are intended to be nonrestrictive regarding the number of instances (i.e. occurrences) of the element or component. Therefore, “a” or “an” is to be read to include one or at least one, and the singular word form of the element or component also includes the plural unless the number is obviously meant to be singular.

[0034] As used herein, the term “about” modifying the quantity of a substance, ingredient, component, or parameter employed refers to variation in the numerical quantity that can occur, for example, through typical measuring and handling procedures, e.g., liquid handling procedures used for making concentrates or solutions. Furthermore, variation can occur from inadvertent error in measuring procedures, differences in the manufacture, source, or purity of the ingredients employed to carry out the invention. In one embodiment, the term “about” means within 10% of the reported numerical value. In a more specific embodiment, the term “about” means within 5% of the reported numerical value.

[0035] As aforementioned, the present invention relates in a first aspect to an antimicrobial composition comprising an alkylene glycol ester and at least one antimicrobial compound selected from the group consisting of citric acid and salts thereof, salicylic acid and salts thereof, gluconolactone, levulinic acid and salts thereof, ethyl levulinate, butyl levulinate, ethylhexyl glycerin, ethylene glycol, 1 ,3-propanediol, 1 ,3-butanediol, 2,3-butanediol, 1 ,2-pentanediol, 1 ,2-hexanediol, caprylyl glycol, ethyl lactate, butyl lactate, climbazole, 1 ,2-decylene glycol, 4-hydroxyacetophenone, caprylhydroxamic acid and salts thereof, glyceryl caprylate, chlorphenesin, triclosan, methylheptylglycerin, polyglyeryl- 2 or 3 or 4 or 6 or 10 -caprylate, polyglyeryl- 2 or 3 or 4 or 6 or 10 -caprate / caprylate, azelaic acid, Vitamin C, zinc oxide, zinc citrate, zinc Pyrrolidone Carboxylic Acid (zinc PCA), zinc glycinate, zinc oxide, niacinamide, hyaluronic acid, 2-methyl-5-cyclohexylpentanol, Aluminium sulphate, Aluminium zirconium, Aluminum chloride, aluminium chlorhydrate, other aluminium salts, benzoyl peroxide, glycolic acid, phenethyl alcohol, 3-phenylpropan-1-ol, anisic acid and salts thereof, 1 ,2-heptanediol, caprylyl glyceryl ether, capryloyl glycine, tetrasodium glutamate diacetate, trisodium dicarboxymethyl alaninate, and phytic acid and salts thereof, wherein said alkylene glycol ester and said antimicrobial compound are present in a weight ratio of about 1 :1000 to about 2500:1 . According to a second aspect, the present invention relates to an antimicrobial composition comprising an alkylene glycol ester and at least one antimicrobial compound selected from the group consisting of citric acid and salts thereof, salicylic acid and salts thereof, gluconolactone, levulinic acid and salts thereof, ethyl levulinate, butyl levulinate, ethylhexyl glycerin, ethylene glycol, 1 ,3-propanediol, 1 ,3-butanediol, 2,3-butanediol, 1 ,2-pentanediol, 1 ,2-hexanediol, caprylyl glycol, ethyl lactate, butyl lactate, climbazole, 1 ,2-decylene glycol, 4-hydroxyacetophenone, caprylhydroxamic acid and salts thereof, glyceryl caprylate, chlorphenesin, triclosan, methylheptylglycerin, polyglyeryl- 2 or 3 or 4 or 6 or 10 -caprylate, polyglyeryl- 2 or 3 or 4 or 6 or 10 -caprate / caprylate, azelaic acid, nonanoic acid, Vitamin C, zinc oxide, zinc citrate, zinc Pyrrolidone Carboxylic Acid (zinc PCA), zinc glycinate, zinc oxide, niacinamide, hyaluronic acid, 2-methyl-5- cyclohexylpentanol, Aluminium sulphate, Aluminium zirconium, Aluminum chloride, aluminium chlorhydrate, other aluminium salts, benzoyl peroxide, glycolic acid, phenethyl alcohol, 3- phenylpropan-1-ol, anisic acid and salts thereof, 1 ,2-heptanediol, caprylyl glyceryl ether, capryloyl glycine, tetrasodium glutamate diacetate, trisodium dicarboxymethyl alaninate, and phytic acid and salts thereof, wherein said alkylene glycol ester and said antimicrobial compound are present in a synergistically effective amount.

[0036] In the following, particular embodiments of the first and second aspect of the present invention such as antimicrobial compounds, ratio, and the like are described in further details. It is to be understood that each embodiment is relevant on its own as well as in combination with other embodiments.

[0037] Embodiments of the present invention include one or more alkylene glycol esters. Alkylene glycol esters useable in the present invention may be formed from saturated, unsaturated, natural or synthetic fatty acids, and the like. For instance, saturated fatty acids include caprylic acid, capric acid, hexanoic acid, dodecanoic acid, lauric acid, myristic acid, palmitic acid, stearic acid, arachidic acid, behenic acid, lignoceric acid, cerotic acid, nonanoic acid, combinations thereof, derivatives thereof, and the like. Fatty acids having a carbon chain length of from about 5 carbon atoms to about 16 carbon atoms are well suited for use in forming the alkylene glycol ester. The alkylene glycol ester can be formed from any suitable alkylene, such as ethylene, butylene or propylene. The alkylene glycol ester can comprise a monoester or a diester. In one aspect, a mixture of monoesters, a mixture of diesters, or a mixture of monoesters and diesters may be incorporated into the composition of the present invention. In one aspect, at least one monoester is utilized and comprises the majority of the alkylene glycol ester present. In some embodiments, the alkylene glycol ester(s) is derived from (a) a propylene glycol, and (b) a fatty acid having from about 6 to 12 carbon atoms, such as caproic acid, caprylic acid, capric acid, lauric acid, and mixtures of the like. For example, propylene glycol C6-C12 fatty acid monoesters or diesters may be used. Propylene glycol C6-C14 fatty acid monoesters or diesters may also be used.

[0038] Suitable examples of alkylene glycol esters, include but are not limited to, propylene glycol isostearate, propylene glycol laurate, propylene glycol myristate, propylene glycol oleate, propylene glycol monolaurate, propylene glycol monocaprate, propylene glycol monocaprylate, propylene glycol monocaproate, propylene glycol diperlargonate, propylene glycol diisostearate, propylene glycol dilaurate, propylene glycol monopalmitate, propylene glycol monostearate, or mixtures thereof, other complexes or derivatives thereof, and the like.

[0039] A suitable example of an alkylene glycol diester is propylene glycol dicaprylate.

[0040] In one embodiment, the alkylene glycol ester is primarily propylene glycol monocaprylate. The propylene glycol monocaprylate can include a mixture of propylene glycol monoesters and diesters. For example, the propylene glycol monocaprylate may contain 2-hydroxylpropyl caprylate (e.g. 40 to 70 wt.-%), octanoic acid-2-hydroxy-1 -methylethyl ester (e.g. 23 to 33 wt.-%), and 1 ,2-propylene glycol dicaprylate (e.g. 5 to 28 wt.-%).

[0041] In one embodiment, the alkylene glycol ester comprises propylene glycol caprylate (PGC). In one embodiment, the alkylene glycol ester comprises a mixture of at least one propylene glycol monocaprylate and propylene glycol dicaprylate. In one embodiment, the alkylene glycol ester is of a mixture of at least one propylene glycol monocaprylate and propylene glycol dicaprylate. In one embodiment, the at least one propylene glycol monocaprylate is selected from octanoic acid-2- hydroxy-1 -methylethyl ester, 2-hydroxylpropyl caprylate, and a combination thereof. In one embodiment, the at least one propylene glycol monocaprylate is a mixture of octanoic acid-2- hydroxy-1 -methylethyl ester and 2-hydroxylpropyl caprylate. In one embodiment, the propylene glycol dicaprylate is 1 ,2-Propylene glycol dicaprylate. In one embodiment, the alkylene glycol ester comprises at least 50 wt.-% of at least one propylene glycol monocaprylate, preferably at least 60 wt.-% of at least one propylene glycol monocaprylate, more preferably at least 70 wt.-% of at least one propylene glycol monocaprylate, based on the total weight of the alkylene glycol ester. In one embodiment, the at least one propylene glycol monocaprylate and the propylene glycol dicaprylate are comprised in the mixture at a weight ratio of from 15:1 to 1 :1 , preferably at a weight ratio of from 10:1 to 1 :1 , more preferably at a weight ratio of from 5:1 to 2:1 . In one embodiment, the alkylene glycol ester comprises a mixture of octanoic acid-2-hydroxy-1- methylethyl ester, 2-hydroxylpropyl caprylate, and 1 ,2-propylene glycol dicaprylate. In one embodiment, the alkylene glycol ester comprises from 20 wt.-% to 35 wt.-% octanoic acid-2- hydroxy-1 -methylethyl ester, from 40 wt.-% to 70 wt.-% 2-hydroxylpropyl caprylate, and from 5 wt.- % to 30 wt.-% 1 ,2-propylene glycol dicaprylate, based on the total weight of the alkylene glycol ester.

[0042] In one embodiment, the alkylene glycol ester comprises from 20 wt.-% to 30 wt.-% octanoic acid-2- hydroxy-1 -methylethyl ester, from 40 wt.-% to 60 wt.-% 2-hydroxylpropyl caprylate, and from 20 wt.- % to 30 wt.-% 1 ,2-propylene glycol dicaprylate, based on the total weight of the alkylene glycol ester.

[0043] In one embodiment, the alkylene glycol ester comprises from 20 wt.-% to 40 wt.-% octanoic acid-2- hydroxy-1 -methylethyl ester, from 50 wt.-% to 70 wt.-% 2-hydroxylpropyl caprylate, and from 5 wt.- % to 15 wt.-% 1 ,2-propylene glycol dicaprylate, based on the total weight of the alkylene glycol ester.

[0044] In some embodiments, the alkylene glycol ester may not include a propylene glycol monoester derived from a propylene glycol component and a fatty acid having equal to or more than 16, carbons such as palmitic acid. While not being bound by any particular theory, it has been discovered that the combination of an antimicrobial compound and a propylene glycol monoester containing C16 fatty acid, may not provide additive or synergistic benefits. Accordingly, in certain embodiments, the alkylene glycol ester utilized in the compositions described herein may be substantially free of a propylene glycol monoester containing a C16 fatty acid, such as palmitic acid.

[0045] In one embodiment, said alkylene glycol ester comprises propylene glycol ester, preferably propylene glycol caprylate, and in particular propylene glycol monocaprylate. In one embodiment, said alkylene glycol ester is propylene glycol ester, such as propylene glycol caprylate or propylene glycol monocaprylate.

[0046] In one embodiment, said alkylene glycol ester comprises alkylene glycol caprylate such as selected from the group consisting of alkylene glycol monocaprylate, alkylene glycol dicaprylate, and mixtures thereof.

[0047] In one embodiment, said alkylene glycol ester is selected from the group consisting of alkylene glycol monoester, alkylene glycol diester, and mixtures thereof, preferably selected from the group consisting of propylene glycol monoester, propylene glycol diester, and mixtures thereof, and in particular selected from the group consisting of propylene glycol monocaprylate, propylene glycol dicaprylate, and mixtures thereof.

[0048] In one embodiment, said alkylene glycol ester is a mixture of alkylene glycol monoester and alkylene glycol diester comprising at least 10 wt.-%, preferably at least 30 wt.-%, more preferably at least 50 wt.-%, still more preferably at least 60 wt.-%, and in particular at least 70 wt.-%, of the alkylene glycol monoester, based on the weight sum of alkylene glycol monoester and propylene glycol diester. In one embodiment, said alkylene glycol ester is a mixture of alkylene glycol monocaprylate and alkylene glycol dicaprylate comprising at least 10 wt.-%, preferably at least 30 wt.-%, more preferably at least 50 wt.-%, still more preferably at least 60 wt.-%, and in particular at least 70 wt.-%, of the alkylene glycol monocaprylate, based on the weight sum of alkylene glycol monocaprylate and propylene glycol dicaprylate. In one embodiment, said alkylene glycol ester is a mixture of propylene glycol monocaprylate and propylene glycol dicaprylate comprising at least 10 wt.-%, preferably at least 30 wt.-%, more preferably at least 50 wt.-%, still more preferably at least 60 wt.-%, and in particular at least 70 wt.-%, of the propylene glycol monocaprylate, based on the weight sum of propylene glycol monocaprylate and propylene glycol dicaprylate.

[0049] In one embodiment, said alkylene glycol ester comprises a mixture of at least one propylene glycol monocaprylate and propylene glycol dicaprylate. In one embodiment, said alkylene glycol ester comprises at least 50 wt.-% of at least one propylene glycol monocaprylate, preferably at least 60 wt.-% of at least one propylene glycol monocaprylate, more preferably at least 70 wt.-% of at least one propylene glycol monocaprylate, based on the total weight of the alkylene glycol ester. In one embodiment, the at least one propylene glycol monocaprylate and the propylene glycol dicaprylate are comprised in the mixture at a weight ratio of from about 15:1 to about 1 :1 , preferably at a weight ratio of from about 10:1 to about 1 :1 , more preferably at a weight ratio of from about 5:1 to about 2:1.

[0050] The weight ratio of said alkylene glycol ester and that at least one antimicrobial compound can vary depending on a variety of factors. For example, said weight ratio can depend on the composition of the final product, the microorganisms that are being controlled, the particular alkylene glycol ester and antimicrobial compound used, the final properties of the product, and the like. The weight ratio of said alkylene glycol ester to the at least one antimicrobial compound, for instance, can be in the range of about 1 :50,000 to about 500:1 , such as from about 1 :10,000 to about 400:1 , such as from about 1 :5,000 to about 200:1 , such as from about 1 :2,500 to about 100:1 , such as from about 1 :1 ,500 to about 50:1 , such as from about 1 :1 ,000 to 30:1 . In many applications, only a small amount of alkylene glycol ester is needed in order to enhance the efficacy of the at least one antimicrobial compound. For example, in one aspect, the at least one antimicrobial compound is present in greater amounts than said alkylene glycol ester. In certain embodiments, the weight ratio of said alkylene glycol ester to the at least one antimicrobial compound can be from about 1 :5,000 to about 4:1 , such as from about 1 :1 ,500 to about 4:1 , such as from about 1 :300 to about 4:1 , such as from about 1 :20 to about 4:1 , such as from about 1 :15 to about 4:1 , such as from about 1 :10 to about 4:1 . In one embodiment, the at least one antimicrobial compound and said alkylene glycol ester are comprised in the antimicrobial composition at a weight ratio of from 1 :1 to 6:1 . In one embodiment, the at least one antimicrobial compound and said alkylene glycol ester are comprised in the antimicrobial composition at a weight ratio of from 1 .1 :1 to 3:1 . In one embodiment, the at least one antimicrobial compound and said alkylene glycol ester are comprised in the antimicrobial composition at a weight ratio of from 1 .2:1 to 2:1 .

[0051] In one embodiment, said alkylene glycol ester and said antimicrobial compound are present in a synergistically effective weight ratio.

[0052] In one embodiment, said alkylene glycol ester and said antimicrobial compound are present in a weight ratio of about 1 :1000 to about 2000:1 , or about 1 :1000 to about 1500:1 , or about 1 :1000 to about 500:1 , or about 1 :1000 to about 50:1 , or about 1 :800 to about 200:1 , or about 1 :800 to about 40:1 , or about 1 :600 to about 150:1 , or about 1 :600 to about 30:1 , or about 1 :550 to about 100:1 , or about 1 :550 to about 20:1 . In one embodiment, said alkylene glycol ester and said antimicrobial compound are present in a weight ratio of about 1 :500 to about 2000:1 , or about 1 :200 to about 2000:1 , or about 1 :50 to about 1500:1 , or about 1 :10 to about 1300:1 .

[0053] The salts of citric acid, salicylic acid, levulinic acid, anisic acid, and phytic acid may be any known in the art salts thereof. Suitable cationic counterions are e.g. the ions of alkali metals, preferably lithium, sodium and potassium, of the alkaline earth metals, preferably calcium, magnesium and barium, and of the transition metals preferably manganese, copper, silver, zinc and iron, and also ammonium (NH4+) and substituted ammonium in which one to four of the hydrogen atoms are replaced by C1-C4-alkyl, C1-C4-hydroxyalkyl, C1-C4-alkoxy, C1-C4-alkoxy-C1-C4alkyl, hydroxyCi -C4-alkoxy-C1-C4-alkyl, phenyl or benzyl. Suitably, the salt of said acids is the sodium salt such as the salt of salicylic acid is sodium salicylate.

[0054] In one embodiment, the at least one antimicrobial compound is selected from the group consisting of citric acid and salts thereof, salicylic acid and salts thereof, gluconolactone, levulinic acid and salts thereof, ethyl levulinate, butyl levulinate, ethylhexyl glycerin, ethylene glycol, 1 ,3-propanediol, 1 ,3-butanediol, 2,3-propanediol, 1 ,2-pentanediol, 1 ,2-hexanediol, caprylyl glycol, ethyl lactate, butyl lactate, climbazole, 1 ,2-decylene glycol, 4-hydroxyacetophenone, caprylhydroxamic acid and salts thereof, glyceryl caprylate, chlorphenesin, triclosan, methylheptylglycerin, polyglyeryl- 2 or 3 or 4 or 6 or 10 -caprylate, polyglyeryl- 2 or 3 or 4 or 6 or 10 -caprate / caprylate, azelaic acid, Vitamin C, zinc oxide, zinc citrate, zinc Pyrrolidone Carboxylic Acid (zinc PCA), zinc glycinate, niacinamide, hyaluronic acid, 2-methyl-5-cyclohexylpentanol, Aluminium sulphate, Aluminium zirconium, Aluminum chloride, aluminium chlorhydrate, and benzoyl peroxide.

[0055] In one embodiment, the least one antimicrobial compound is selected from the group consisting of citric acid and salts thereof, salicylic acid and salts thereof, gluconolactone, levulinic acid and salts thereof, ethyl levulinate, butyl levulinate, ethylhexyl glycerin, ethylene glycol, 1 ,3-propanediol, 1 ,3-butanediol, 2,3-propanediol, 1 ,2-pentanediol, 1 ,2-hexanediol, caprylyl glycol, ethyl lactate, methylheptylglycerin, zinc glycinate, and butyl lactate such as citric acid and sodium salicylate.

[0056] In one embodiment, the at least one antimicrobial compound is selected from the group consisting of levulinic acid and salts thereof, ethyl levulinate, and butyl levulinate, such as selected from the group consisting of levulinic acid, ethyl levulinate, and butyl levulinate, preferably is levulinic acid.

[0057] In one embodiment, the at least one antimicrobial compound is selected from the group consisting of ethylene glycol, 1 ,3-propanediol, 1 ,3-butanediol, 2,3-butanediol, 1 ,2-pentanediol, 1 ,2-hexanediol, and caprylyl glycol.

[0058] In one embodiment, the at least one antimicrobial compound is selected from the group consisting of ethyl lactate and butyl lactate.

[0059] In one embodiment, the at least one antimicrobial compound is selected from the group consisting of ethyl levulinate, butyl levulinate, ethyl lactate, and butyl lactate.

[0060] In one embodiment, the at least one antimicrobial compound is selected from the group consisting of citric acid and salts thereof, salicylic acid and salts thereof, and levulinic acid and salts thereof, such as selected from the group consisting of citric acid, sodium salicylate, and levulinic acid, preferably selected from the group consisting of citric acid and levulinic acid.

[0061] In one embodiment, said alkylene glycol ester is propylene glycol caprylate (PGC), such as selected from the group consisting of propylene glycol monocaprylate, propylene glycol dicaprylate, and mixtures thereof, and said antimicrobial compound is citric acid, and wherein said PGC and said citric acid are present in a weight ratio of about 1 :32 to about 200:1 .

[0062] In one embodiment, said alkylene glycol ester is propylene glycol caprylate (PGC), such as selected from the group consisting of propylene glycol monocaprylate, propylene glycol dicaprylate, and mixtures thereof, and said antimicrobial compound is sodium salicylate, and wherein said PGC and said sodium salicylate are present in a weight ratio of about 1 :128 to about 20:1 .

[0063] In one embodiment, said alkylene glycol ester is propylene glycol caprylate (PGC), such as selected from the group consisting of propylene glycol monocaprylate, propylene glycol dicaprylate, and mixtures thereof, and said antimicrobial compound is gluconolactone, and wherein said PGC and said gluconolactone are present in a weight ratio of about 1 :128 to about 80:1.

[0064] In one embodiment, said alkylene glycol ester is propylene glycol caprylate (PGC), such as selected from the group consisting of propylene glycol monocaprylate, propylene glycol dicaprylate, and mixtures thereof, and said antimicrobial compound is levulinic acid, ethyl levulinate, or butyl levulinate, and wherein said PGC and said levulinic acid, ethyl levulinate, or butyl levulinate are present in a weight ratio of about 1 :256 to about 5:1 .

[0065] In a preferred embodiment, said antimicrobial compound is levulinic acid, and wherein said alkylene glycol ester selected from the group consisting of propylene glycol monocaprylate, propylene glycol dicaprylate, and mixtures thereof and said levulinic acid are present in a weight ratio of about 1 :256 to about 5:1 .

[0066] In a preferred embodiment, said alkylene glycol ester comprises a mixture of octanoic acid-2- hydroxy-1 -methylethyl ester, 2-hydroxylpropyl caprylate, and 1 ,2-propylene glycol dicaprylate and the at least one antimicrobial compound comprises levulinic acid. In a preferred embodiment, the mixture of octanoic acid-2-hydroxy-1 -methylethyl ester, 2-hydroxylpropyl caprylate and 1 ,2- propylene glycol dicaprylate and the levulinic acid are comprised in the antimicrobial composition at a weight ratio of about 1 :256 to about 5:1 .

[0067] In another embodiment, said antimicrobial compound is ethyl levulinate or butyl levulinate, and wherein said PGC and said ethyl levulinate or butyl levulinate are present in a weight ratio of about 1 :256 to about 1 :1.

[0068] In one embodiment, said alkylene glycol ester is propylene glycol caprylate (PGC), such as selected from the group consisting of propylene glycol monocaprylate, propylene glycol dicaprylate, and mixtures thereof, and said antimicrobial compound is ethylhexyl glycerin, and wherein said PGC and said ethylhexyl glycerin are present in a weight ratio of about 1 :32 to about 4:1 .

[0069] In one embodiment, said alkylene glycol ester is propylene glycol caprylate (PGC), such as selected from the group consisting of propylene glycol monocaprylate, propylene glycol dicaprylate, and mixtures thereof, and said antimicrobial compound is caprylyl glycol, 1 ,2-pentanediol, or 1 ,2- hexanediol, and wherein said PGC and said caprylyl glycol, 1 ,2-pentanediol, or 1 ,2-hexanediol are present in a weight ratio of about 1 :256 to about 5:1 , preferably wherein said antimicrobial compound is caprylyl glycol, and wherein said PGC and said caprylyl glycol are present in a weight ratio of about 1 :8 to about 5:1 or wherein said antimicrobial compound is 1 ,2-pentanediol, and wherein said PGC and said 1 ,2-pentanediol are present in a weight ratio of about 1 :256 to about 2:13, or wherein said antimicrobial compound is 1 ,2-hexanediol, and wherein said PGC and said

[0070] 1 .2-hexanediol are present in a weight ratio of about 1 :128 to about 4:13.

[0071] In one embodiment said alkylene glycol ester is propylene glycol caprylate (PGC), such as selected from the group consisting of propylene glycol monocaprylate, propylene glycol dicaprylate, and mixtures thereof, and said antimicrobial compound is ethylene glycol, 1 ,3-propanediol, or 1 ,3- butanediol, and wherein said PGC and said ethylene glycol, 1 ,3-propanediol, 1 ,3-butanediol or 2,3- butanediol are present in a weight ratio of about 1 :256 to about 10:1 , preferably wherein said antimicrobial compound is ethylene glycol, and wherein said PGC and said ethylene glycol are present in a weight ratio of about 1 :256 to about 10:1 , or wherein said antimicrobial compound is

[0072] 1 .3-propanediol, and wherein said PGC and said 1 ,3-propanediol are present in a weight ratio of about 1 :128 to about 5:1 , or wherein said antimicrobial compound is 1 ,3-butanediol, and wherein said PGC and said 1 ,3-butanediol are present in a weight ratio of about 1 : 128, or wherein said antimicrobial compound is 2,3-propanediol, and wherein said PGC and said 2,3-propanediol are present in a weight ratio of about 1 :128 to about 5:1 , or wherein said antimicrobial compound is 2,3- butanediol, and wherein said PGC and said 2,3-butanediol are present in a weight ratio of about 1 :128.

[0073] In one embodiment, said alkylene glycol ester is propylene glycol caprylate (PGC), such as selected from the group consisting of propylene glycol monocaprylate, propylene glycol dicaprylate, and mixtures thereof, and said antimicrobial compound is ethyl lactate or butyl lactate, and wherein said PGC and said ethyl lactate or butyl lactate are present in a weight ratio of about 1 :512 to about 1 :1 , preferably wherein said antimicrobial compound is ethyl lactate, and wherein said PGC and said ethyl lactate are present in a weight ratio of about 1 :512 to about 1 :1 or wherein said antimicrobial compound is butyl lactate, and wherein said PGC and said butyl lactate are present in a weight ratio of about 1 : 128 to about 1 : 1 .

[0074] In one embodiment, said alkylene glycol ester is propylene glycol caprylate (PGC), such as selected from the group consisting of propylene glycol monocaprylate, propylene glycol dicaprylate, and mixtures thereof, and said antimicrobial compound is methylheptylglycerin, and wherein said PGC and said methylheptylglycerin are present in a weight ratio of about 1 :4 to about 32:1 . In one embodiment, said alkylene glycol ester is propylene glycol caprylate (PGC), such as selected from the group consisting of propylene glycol monocaprylate, propylene glycol dicaprylate, and mixtures thereof, and said antimicrobial compound is zinc glycinate, and wherein said PGC and said zinc glycinate are present in a weight ratio of about 2:1 to about 500:1 .

[0075] In one embodiment, said alkylene glycol ester is propylene glycol caprylate (PGC), such as selected from the group consisting of propylene glycol monocaprylate, propylene glycol dicaprylate, and mixtures thereof, and said antimicrobial compound is zinc Pyrrolidone Carboxylic acid, and wherein said PGC and said zinc Pyrrolidone Carboxylic acid are present in a weight ratio of about 1 :1 to about 2000:1 .

[0076] In one embodiment, said alkylene glycol ester is propylene glycol caprylate (PGC), such as selected from the group consisting of propylene glycol monocaprylate, propylene glycol dicaprylate, and mixtures thereof, and said antimicrobial compound is hyaluronic acid, and wherein said PGC and said hyaluronic acid are present in a weight ratio of about 1 :1 to about 1250:1 .

[0077] In one embodiment, said alkylene glycol ester is propylene glycol caprylate (PGC), such as selected from the group consisting of propylene glycol monocaprylate, propylene glycol dicaprylate, and mixtures thereof, and said antimicrobial compound is and glycolic acid, and wherein said PGC and said and glycolic acid are present in a weight ratio of about 1 :8 to about 2:1 .

[0078] In one embodiment, said alkylene glycol ester is propylene glycol caprylate (PGC), such as selected from the group consisting of propylene glycol monocaprylate, propylene glycol dicaprylate, and mixtures thereof, and said antimicrobial compound is nonanoic acid, and wherein said PGC and said nonanoic acid are present in a weight ratio of about 1 :1 to 8:1 .

[0079] In one embodiment, the antimicrobial composition comprises

[0080] (i) the at least one antimicrobial compound, such as levulinic acid; and

[0081] (ii) a mixture of octanoic acid-2-hydroxy-1 -methylethyl ester, 2-hydroxylpropyl caprylate, and 1 ,2-propylene glycol dicaprylate.

[0082] In one embodiment, the antimicrobial composition comprises

[0083] (i) from about 10 to about 90 wt.-%, of the at least one antimicrobial compound, such as levulinic acid; and

[0084] (ii) from about 10 to about 80 wt.-%, of said alkylene glycol ester, preferably derived from (a) an alkylene glycol, and (b) a fatty acid having from about 6 to 14 carbon atoms; wherein the amounts are based on the total weight of the antimicrobial composition. In one embodiment, the antimicrobial composition comprises

[0085] (i) from about 10 to about 90 wt.-%, of the at least one antimicrobial compound, such as levulinic acid; and

[0086] (ii) from about 10 to about 80 wt.-%, of a mixture of octanoic acid-2-hydroxy-1 -methylethyl ester, 2-hydroxylpropyl caprylate and 1 ,2-propylene glycol dicaprylate; wherein the amounts are based on the total weight of the antimicrobial composition.

[0087] In certain embodiments, the antimicrobial composition disclosed herein may have a pH of from about 2 to about 11 , such as from about 3 to about 10, particularly from about 3 to about 8.

[0088] The present invention further pertains to an end-use formulation comprising the antimicrobial composition according to the present invention. The amount of the at least one antimicrobial compound used in the end-use formulation of the present invention varies, as described above, depending on the particular at least one antimicrobial compound. In an alternative embodiment, the at least one antimicrobial compound may be formulated in the form of an antimicrobial concentrate. By “antimicrobial concentrate” or “antimicrobial composition” it is meant a composition which is to be added to an end-use formulation in a specified amount. In the antimicrobial concentrate, the amount of the at least one antimicrobial compound will be higher than final use amounts formulated in enduse products. In certain embodiments, the antimicrobial concentrate may contain only the at least one antimicrobial compound and said alkylene glycol ester. Alternatively, in certain embodiments, the antimicrobial concentrate may contain the at least one antimicrobial compound, said alkylene glycol ester and a carrier that is compatible with end-use formulations. Exemplary carriers include, for example, water, an aqueous solvent or other solvents acceptable for end-use formulations and uses of these formulations. The antimicrobial concentrate can be added to end-use formulation in an amount necessary to achieve the desired amount of the at least one antimicrobial compound in the final end-use formulation.

[0089] When contained in an antimicrobial concentrate, the at least one antimicrobial compound and said alkylene glycol ester may be combined with various different components. For instance, in one embodiment, the antimicrobial concentrate may contain a solvent. The solvent can be a polar solvent such as water, or a water-miscible solvent, such as an alcohol and / or a glycol ether. In certain embodiments, the antimicrobial composition can further include a water-miscible organic solvent. Examples of suitable water-miscible solvents include ethanol, propanol, benzyl alcohol, isopropanol, diethylene glycol propyl ether, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monoisopropyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monobutyl ether, diethylene glycol monoethyl ether, diethylene glycol mono-n-butyl ether, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol dibutyl ether, propylene glycol n-butyl ether, tripropylene glycol methyl ether, dipropylene glycol methyl ether, dipropylene glycol butyl ether and combinations thereof.

[0090] In other embodiments, one or more alkylene glycol esters and the at least one antimicrobial compound may be added to an end-use formulation independent of each other. For example, in certain embodiments said alkylene glycol ester may be added to the at least one antimicrobial compound prior to the addition of the at least one antimicrobial compound to the end-use formulation. Still in some embodiments, said alkylene glycol ester may be added to end-use formulation after the at least one antimicrobial compound is added to the end-use formulation. In some embodiments, said alkylene glycol ester may be added to the end-use formulation prior to the addition of the at least one antimicrobial compound to the end-use formulation. In certain embodiments, said alkylene glycol ester may be added concurrently with the at least one antimicrobial compound to the end-use formulation as separate ingredients.

[0091] As aforementioned, the present invention relates in a third aspect to an end-use formulation, preferably a home care or personal care product, comprising the antimicrobial composition according to the present invention.

[0092] Embodiments regarding the respective antimicrobial composition are already above-described and shall hold for the end-use formulation such as home care or personal care product, as well. Additional embodiments are described in the following.

[0093] In some embodiments, the antimicrobial composition of the present invention may be added to an end-use formulation, such as the home care or personal care product, in an amount between 0.01% to about 10% by weight of the formulation. More particularly, in some embodiments the antimicrobial composition is added in an amount which is between about 0.1% and 5.0% by weight of the formulation. The amount of the antimicrobial composition added may be dependent on the antimicrobial compound selected.

[0094] In one embodiment, the antimicrobial composition has a weight of 0.02 to 10% based on the total weight of the end-use formulation such as home care or personal care product. In one embodiment, said alkylene glycol ester comprised in the antimicrobial composition is present in the end-use formulation such as home care or personal care product in an amount of from 10 wt.- % or less, such as in an amount of 5 wt.-% or less, based on the weight of the end-use formulation such as home care or personal care product.

[0095] In one embodiment, the at least one antimicrobial compound comprised in the antimicrobial composition is present in the end-use formulation such as home care or personal care product in an amount of from 10 wt.-% or less, such as in an amount of 5 wt.-% or less, based on the weight of the end-use formulation such as home care or personal care product.

[0096] In one embodiment, the antimicrobial composition is levulinic acid or salts thereof, ethyl levulinate, or butyl levulinate, preferably wherein said antimicrobial compound is levulinic acid.

[0097] In general, the antimicrobial composition of the present invention can be incorporated into any number of different end-use formulations or products. As used herein, “end-use formulations” or “end-use products” is intended to mean personal care products, including cosmetics, home care products, and health and hygiene products.

[0098] In one embodiment, the personal care product is selected from the group consisting of shampoo, skin lotion, shower gel, deodorant, bubble bath, bath oil, cream, baby product, liquid soap, hair gel, hair conditioner, hair conditioning mask, hair styling product, make-up, sunscreen, colour cosmetic, toothpaste, mouthwash, and wet wipe.

[0099] For instance, personal care products may include products such as cosmetic formulations, including face creams, makeup removers, mascaras or wet wipes. The personal care product formulation also includes shampoos, conditioners, skin lotions or liquids for any personal care wet wipe application. The personal care product formulation can include any product for topical application to a user's skin or hair. When the antimicrobial compositions disclosed herein are formulated into a personal care product, the antimicrobial composition provides effective, broad spectrum antimicrobial activity over a broad pH range. For instance, in certain embodiments, the personal care product may have a pH ranging from about 2 to 11 , such as from about 3 to about 10, particularly from about 3 to about 8. Accordingly, the antimicrobial composition disclosed herein may exhibit broad antimicrobial coverage for the end-use product across a range of end-use products having a spectrum of pHs.

[0100] The personal care product formulation may comprise a base formulation to which the antimicrobial composition of the present invention is added. The base formulation may contain numerous and different ingredients depending upon the end use application. The personal care product formulation, for instance, may contain solvents, surfactants, emulsifiers, consistency factors, conditioners, emollients, skin caring ingredients, moisturizers, thickeners, humectants, fillers, antioxidants, preservation agents, active ingredients, in particular dermatologically active ingredients, fragrances and the like, as well as mixtures thereof. Active ingredients as mentioned herein comprise, for example, anti-inflammatories, anti-bacterials, anti-fungals and the like agents. Active ingredients suited for topical applications are particularly preferred.

[0101] Suitable surfactants comprise: alkyl sulfates e.g. sodium lauryl sulfate, ammonium lauryl sulfate; sodium cetearyl sulfate; alkyl sulfoacetates e.g. sodium lauryl sulfoacetate; alkyl ether sulfates e.g. sodium laureth sulfate; sodium trideceth sulfate; sodium oleth sulfate; ammonium laureth sulfate; alkyl ether sulfosuccinates e.g. disodium laureth sulfosuccinate; alkyl glycosides e.g. decyl glucoside; lauryl glucoside; alkyl isethionates amphoterics e.g. cocamidopropyl betaine; sodium cocoamphoacetate; sodium lauroamphoacetate; disodium lauroamphodiacetate; disodium cocoamphodiacetate; sodium lauroamphopripionate; disodium lauroamphodipropionate; potassium or ammonium salts of the aforementioned amphoterics; capryl / capramidopropyl betaine; undecylenamidopropyl betaine; lauromidopropyl betaine; and fatty alcohol polyglycol ethers.

[0102] Suitable emulsifiers include e.g. anionics as salts of fatty acids e.g. sodium stearate or sodium palmitate, organic soaps e.g. mono-, di- or triethanolaminoeate, sulfated or sulfonated compounds e.g. sodium lauryl sulfate or sodium cetyl sulfonate, saponines, lamepones; cationics as quaternary ammonium salts; nonionics as fatty alcohols, fatty acid ester with saturated or unsaturated fatty acids, polyoxyethylenesters or polyoxyethylenethers of fatty acids, polymers from ethylene oxide and propylene oxide or propylene glycol, amphotherics as phosphatides, proteins as gelatine, casein alkylamidobetaines, alkyl betaines and amphoglycinates, alkyl phosphates, alkylpolyoxyethylene phosphates or the corresponding acids, silicone derivatives, e.g. alkyl dimethiconecoplyol.

[0103] Suitable consistency factors include e.g. fatty alcohols or their mixtures with fatty acid esters, e.g. acetylated lanolin alcohol, aluminum stearates, carbomer, cetyl alcohol, glyceryl oleate, glyceryl stearate, glyceryl stearate (and) PEG 100 stearate, magnesium stearate, magnesium sulfate, oleic acid, stearic acid, stearyl alcohol, myristyl myristate, isopropyl palmitate, beeswax and synthetic equivalents thereof, carbomers, and the like. Suitable conditioners are e.g. alkylamido ammonium lactate, cetrimonium chloride and distearoylethyl hydroxyethylmonium methosulfate and cetearyl alcohol, cetyl dimethicone, cetyl ricinoleate, dimethicone, laureth-23, laureth-4, polydecene, retinyl palmitate, quaternized protein hydrolysates, quaternized cellulose and starch derivatives, quaternized copolymers of acrylic or methacrylic acid or salts, quaternized silicone derivatives.

[0104] Suitable emollients include e.g. cetearyl isononanoate, cetearyl octanoate, decyl oleate, isooctyl stearate, coco caprylate / caprate, ethylhexyl hydroxystearate, ethylhexyl isononanoate, isopropyl isostearate, isopropyl myristate, oleyl oleate, hexyl laurate, paraffinum liquidum, PEG-75 lanolin, PEG-7 glyceryl cocoate, petrolatum, ozokerite cyclomethicone, dimethicone, dimethicone copolyol, dicaprylyl ether, butyrospermum parkii, buxus chinensis, canola, carnauba cera, copernicia cerifera, oenothera biennis, elaeis guineensis, prunus dulcis, squalane, zea mays, glycine soja, helianthus annuus, lanolin, hydrogenated castor oil, hydrogenated coconut oil, hydrogenated polyisobutene, sucrose cocoate, stearoxy dimethicone, lanolin alcohol, isohexadecane.

[0105] Suitable skin care ingredients include e.g. plant extracts, bisabolol, anti-inflammatory agents, urea, allantoin, panthenol and panthenol derivatives, phytantriol, vitamins A, E, C, D, ceramides of animal or plant origin, lecithins, and the like.

[0106] Suitable moisturizers include e.g. butylenes glycol, cetyl alcohol, dimethicone, dimyristyl tartrate, glucose glycereth-26, glycerin, glyceryl stearate, hydrolyzed milk protein, lactic acid, lactose and other sugars, laureth-8, lecithin, octoxyglycerin, PEG-12, PEG 135, PEG-150, PEG-20, PEG-8, pentylene glycol, hexylene glycol, phytantriol, poly quaternium-39 PPG-20 methyl glucose ether, propylene glycol, sodium hyaluronate, sodium lactate, sodium PCA, sorbitol, succinoglycan, synthetic beeswax, tri-C14-15 alkyl citrate, starch.

[0107] Suitable thickeners include e.g. acrylates / steareth-20 methacrylate copolymer, carbomer, carboxymethyl starch, cera alba, dimethicone / vinyl dimethicone crosspolymer, propylene glycol alginate, hydroxyethylcellulose, hydroxypropyl methylcellulose, silica, silica dimethyl silylate, xanthan gum, hydrogenated butylenes / ethylene / styrene copolymer.

[0108] Suitable humectants include e.g. adipic acid, fumaric acid and its salts, benzoic acid and its salts, glycerine triacetate, sodium or magnesium lauryl sulfate, magnesium stearate, solid polyethylenglycol, polyvinylpyrrolidone, boric acid, mono-laurate or mono-palmitate, myristyl alcohol, cetyl alcohol, cetylstearyl alcohol, talcum, calcium or magnesium salts of higher fatty acids, mono-, di- or triglycerides of higher fatty acids, polytetrafluorethylene.

[0109] Suitable antioxidants include e.g. sulfites, e.g. sodium sulfite, tocopherol or derivates thereof, ascorbic acid or derivates thereof, citric acid, propyl gallate, chitosan glycolate, cysteine, N-acetyl cysteine plus zinc sulfate, thiosulfates, e.g. sodium thiosulfate, polyphenols and the like. Suitable preservation agents may include, for example, acids, esters, ethers and their salts, , ketones, phenolic compounds, sulfites and chelators, aromatic alcohols, quaternary ammonium compounds, aldehydes, pyrone compounds, urea compounds, imidazole compounds, isothiazolinones, amines, amides, halogen compounds, and combinations thereof.

[0110] In one embodiment, the preservation agent may be an acid compound, including both aromatic and non-aromatic acids. Exemplary acids include, for example, benzoic acid, propionic acid, salicylic acid, sorbic acid, formic acid, undec-10-enoic acid, lactic acid, citric acid and glycolic acid. In addition, salts of these acids may also be used as well as esters of these acids. Examples of salts include sodium benzoate and potassium sorbate. Other salts may also be used. Acid compounds are typically used as preservation agents in end-use formulations in amounts of up to about 3% by weight, depending on the particular acid compound. Similar amounts may be used for the esters and salts. In most cases and used, the amount of the acid, ester or salts thereof are used in amounts up about 1 % by weight, more typically up to about 0.6% by weight. Mixtures of acids may also be used as the preservation agent.

[0111] In another embodiment, the preservation agent may be an aldehyde. Exemplary aldehydes include, for example, formaldehyde and paraformaldehydes. Exemplary aldehyde forming agents include imidazolidine compounds like hydantoins, such as dimethylol dimethyl hydantoin, (DMDMH) and other similar aldehyde forming hydantoins. Depending on the use, the aldehydes may be present in the composition to be preserved in amounts up to 0.3% by weight. Typically, the amount of the aldehydes is up to 0.2% based on the weight of the composition to be preserved. Mixtures of aldehydes may also be used as the preservation agent.

[0112] In a further embodiment, the preservation agent may be a phenolic compound. Exemplary phenolic compounds include, for example, paraben compounds, biphenyl-2-ol (o-phenylphenol) or salts thereof, 4-chloro-m-cresol, 4-Chloro-3,5-dimethylphenol, 4-isopropyl-m-cresol, 2-benzyl-4- chlorophenol, 2-Phenoxyethan-1-ol, chlorphenesin, 3-phenylpropan-1-ol, 2-phenylethanol and bromchlorophen. Exemplary paraben compounds include, for example butyl paraben, propyl paraben, ethyl paraben, methyl paraben and salts thereof, including, for example, potassium, sodium and / or calcium salts. Phenolic compounds are typically used as preservation agents in enduse formulation in amounts up to about 1 % by weight, based on the weight of the total end-use formulation. This upper limit depends on the particular phenolic compound. More typically up to about 0.5% by weight of the phenolic compound is used in cosmetic formulations.

[0113] In yet another embodiment, the preservation agent may be a compound which is a known as chelators such as an iron chelator. Exemplary iron chelators include pyrithione compounds and compounds such as piroctone olamine or hydroxyl pyridine compounds and salts thereof. Pyrithione is known by several names, including 2 mercaptopyridine-N- oxide; 2-pyridinethiol-1 -oxide (CAS Registry No. 1 121-31-9); 1-hydroxypyridine-2-thione and 1 hydroxy-2(1 H)-pyridinethione (CAS Registry No. 1 121-30-8); 2-pyridinol-1 -oxide (HPNO) and N-hydroxy-6-octyloxypyridine 2(1 H)-one and -hydroxy-6-octyloxypyridine 2(1 H)-one ethanolamine salt. Pyrithione salts are commercially available from Arxada AG, such as Sodium OMADINE® or Zinc OMADINE®.

[0114] The pyrithione present as the preservation agent can be present in a water insoluble form or in a water-soluble form. The pyrithione may comprise sodium pyrithione, zinc pyrithione, barium pyrithione, strontium pyrithione, copper pyrithione, cadmium pyrithione, and / or zirconium pyrithione. Other pyrithiones that may be present in the composition include sodium pyrithione, bismuth pyrithione, potassium pyrithione, lithium pyrithione, ammonium pyrithione, calcium pyrithione, magnesium pyrithione, silver pyrithione, gold pyrithione, manganese pyrithione, and / or an organic amine pyrithione. A single pyrithione may be present as the preservation agent or a combination of any of the above may be included as the preservation agent.

[0115] Iron chelator compounds are typically used as preservation agents in end-use formulations in amounts up to about 1% by weight, depending on the particular compound. Of particular interest are zinc pyrithione and piroctone olamine. These iron chelators may also have other advantages, such as providing other benefits, including antidandruff properties.

[0116] In another embodiment, the preservation agent may include inorganic sulfite compounds and hydrogen sulfites compounds. Sulfite compound are generally present in amounts up about 0.5% by weight, based on the total weight of the end-use formulation.

[0117] In some embodiments, the preservation agent includes alcohol compounds. The alcohol may be a lower alcohol or an aromatic alcohol. Lower alcohols are typically selected among mono-functional low-molecular alcohols, preferably alkanols with one to four carbon atoms such as methanol, ethanol, isopropanol or butanol, or combinations thereof. Substituted alcohols, such a chlorobutanol may also be used. Particularly suitable lower alcohols include ethanol and isopropyl alcohol. Aromatic alcohols may also be used. Suitable aromatic alcohols include phenoxyethanol, 2,4- Dichlorophenyl)methanol, benzyl alcohol, 1-Phenoxypropaneol, chlorphenesin, and benzyl hemiformal. One particularly preferred alcohol is phenoxyethanol. The alcohol compounds may be used as preservation agents in end-use formulations in amounts up to about 1 .5% by weight based on the total weight of the end-use formulation, depending on the particular alcohol compound. In most cases, the amount of the alcohol compounds is typically used in amounts up about 1% by weight, more typically up to about 0.5% by weight, based on the weight of the end-use formulation. In another embodiment, one or more quaternary ammonium compounds may be used as preservation agent. Quaternary ammonium compounds, also known as "quats", typically comprise at least one quaternary ammonium cation with an appropriate anion. Quats will generally have the general formula (1).

[0118] The groups Ri, R2, R3 and R4 can vary within wide limits and possess anti-microbial properties. Typically, at least one, such as at least two, of R1, R2, R3 and R4 is a lower alkyl, meaning having 1 to 4 carbon atoms, such as a methyl, ethyl, propyl or butyl group. In one aspect, at least one, such as least two of R1, R2, R3 and R4 is a longer chain alkyl group of 6 to 24 carbon atoms. R4 can also be a substituted or unsubstituted benzyl group such as an ethylbenzyl group, or an alkoxy group. A- is a monovalent anion or one equivalent of a polyvalent anion of an inorganic or organic acid. Suitable anions for A- are in principle all inorganic or organic anions, in particular halides, for example chloride or bromide, carbonates, bicarbonates, carboxylates, sulfonates, phosphates, propionates, saccharinates, or a mixture thereof. Carboxylates may be derived from lower carboxylic acids or from fatty acids.

[0119] Alkyl, hereinafter, is taken to mean in each case unbranched or branched alkyl groups of the specified number of carbons, but preferably unbranched alkyl groups, and particularly preferably those having an even number of carbon atoms. In particular, this is also taken to mean the homologue mixtures derived from natural raw materials, for example “cocoalkyl”.

[0120] In one embodiment, the quaternary ammonium compound may have the following R groups: R1, R2 and R3 are alkyl groups and R4 is a benzyl group, a C1-18 alkyl group such as a Ce-18 alkyl group, or an alkoxy group such as a group having the structure — [(CH2)2 — O]nR5 where n=1-20 and R5 is hydrogen or an unsubstituted or substituted phenyl, and A- is as described above, such as a monovalent anion or one equivalent of a polyvalent anion of an inorganic or organic acid. For example, R1 is an alkyl group having 1 to 4 carbon atoms and R2 and R3 are independently alkyl groups having 6 to 24 carbon atoms, or R1 and R2 are independently alkyl groups having 1 to 4 carbon atoms and R3 is an alkyl group having 6 to 24 carbon atoms.

[0121] Suitable quaternary ammonium compounds include, for example alkyl (C12-22) trimethyl ammonium bromide, alkyl (C12-22) trimethyl ammonium chloride compounds including, for example cetrimonium bromide, cetrimonium chloride, laurtrimonium bromide, laurtrimonium chloride, steartrimonium bromide, and steartrimonium chloride or mixture thereof, benzethonium compound, including, for example benzalkonium chloride, benzalkonium bromide and benzalkonium saccharinate.

[0122] In one embodiment, the quaternary ammonium compound may comprise a dialkyl ammonium compound, such as a dimethyl dialkyl ammonium compound. In one embodiment, the dimethyl dialkyl ammonium compound may have between about 8 and about 12 carbon atoms, such as from about 8 to about 10 carbon atoms in each of the alkyl groups.

[0123] Examples of dimethyl dialkyl ammonium compounds include dimethyl dioctyl ammonium compounds such as dimethyl dioctyl ammonium chloride, dimethyl didecyl ammonium compounds such as dimethyl didecyl ammonium chloride and the like. Mixtures of dimethyl dialkyl ammonium compounds may also be used, and other anions, such as those described above, may also be used. Commercially available dimethyl dialkyl ammonium compounds include, for example, compositions marketed and sold under the BARDAC®, BARDAP®, BARQUAT®, or CARBOQUAT® trade names by Arxada AG

[0124] Such commercially available examples of dimethyl dialkyl ammonium compounds include dioctyldimethylammonium chloride (available as Bardac® LF and LF-80 from Arxada AG), octyldecyldimethylammonium chloride (available as a mixture of octyldecyldimethylammonium chloride, dioctyldimethylammonium chloride, and didecyldimethyl ammonium chloride as Bardac® 2050 and 2080 from Arxada AG), didecyldimethylammonium chloride (available as Bardac® 2250 and 2280 from Arxada AG), decylisononyldimethylammonium chloride (available as Bardac® 21 from Arxada AG), diisodecyldimethylammonium chloride (available as BTC 99 from Stepan Co. of Northfield, III.), and any combination of any of the foregoing.

[0125] The quaternary ammonium compounds may be included in end-use formulations in amounts up to about 0.2% by weight based on the total weight of the end-use formulation, depending on the particular quaternary ammonium compound. In certain embodiments, the end-use formulation may contain from about 0.1% by weight to about 0.05% by weight, based on the weight of the end-use formulation.

[0126] Exemplary pyrone compounds useable in the present invention as a preservation agent include, for example, dehydroacetic acid and salts thereof. Pyrone compounds may be used in amount up to about 1 .0% by weight, based on the total weight of the end-use formulation. In some embodiments, one or more pyrone compounds may be used in an amount of up to about 0.6% by weight. In some embodiments, the preservation agent may include one or more isothiazolinones. Exemplary isothiazolinones include, for example 5-chloro-2-methyl-isothiazol-3-one (chloromethylisothiazolinone), 2-methyl-isothiazol-3-one (methylisothiazolinone), benzisothiazolinone and mixtures thereof. In certain embodiments, one or more isothizaolinones may be used in an amount of up to about 0.01 % by weight of the end-use formulation.

[0127] One more urea compounds may be used as the preservation agent in certain embodiments, Exemplary urea compounds include, for example, 3-(4-Chlorophenyl)-1-(3,4-dichlorophenyl)urea (triclocarban); 1 ,1 '-methylenebis{3-[4-(hydroxymethyl)-2,5-dioxoimidazolidin-4-yl]urea}; and N- (hydroxymethyl)-N-(dihydroxymethyl-l ,3- dioxo 2,5-imidazolinidyl-4)-N’-(hydroxymethyl) urea. These compounds are typically used in amounts up to about 0.5% by weight of the end-use formulation.

[0128] Exemplary imidazole compounds useable in the present invention as the preservation agent include, for example, 1-(4- chlorophenoxy)-1-(imidazole-1-yl)-3,3-dimethylbutan-2-one); 1 ,3- Bis(hydroxymethyl)-5,5-dimethylimidazolidine-2, 4-dione). In some embodiments, one or more urea compounds may be included in an amount of up to about 0.5% by weight of the end-use formulation.

[0129] In still another aspect, the preservation agent can be an amine compound, such as a triamine compound. Suitable triamine compounds include, but are not limited to, those having the formula where R is a substituted or unsubstituted Ca to Cis alkyl, Ca to Cia alkenyl, Ca to Cia alky ny I, or Ca to Cia cycloalkyl or aryl, and R is optionally interrupted with one or more heteroatoms.

[0130] The term “substituted” as used herein includes compounds substituted with one or more of halogen (such as F, Cl, I, or Br); heteroatomic groups; Ca to Cis alkyl; Ca to Cis alkenyl; Ca to Cis alkynyl; Ca to Cia cycloalkyl; aryl; or carbonyl containing Ca to Cis alkyl, Ca to Cis alkenyl, or Ca to Cis alkynyl groups (such as ketones, esters, ethers, carbonates, or carboxylates).

[0131] Suitable heteroatoms include, but are not limited to, O, N, P, and S.

[0132] Suitable heteroatomic groups include, but are not limited to, — NH2, — NO2, — SO2, — SO3, — PO3, =0, and —OH. The substituent R is preferably unsubstituted Ca to Cis alkyl, Ca to Cia alkenyl, Ca to Cia alky nyl, Ca to Cia cycloalkyl, or aryl. Preferred triamines include, but are not limited to, N,N-bis(3-aminopropyl)- dodecylamine, available as Lbac® 12 from Arxada AG. bis(3-aminopropyl)octylamine, and N,N- bis(3-aminopropyl)-octylamine.

[0133] The amine preservation agent can generally be included in an amount up to about 2% by weight of the end use formulation, and particularly from about 50 ppm to about 200,000 ppm, such as from about 50 ppm to about 500 ppm.

[0134] Other components that may be used as a preservation agent include dibromohexamidine and salts thereof; thiomersal; phyenylmercuric salts; hexetidine; 2-bromo-2-nitropropane-1 ,3-diol; 5-bromo-5- nitro-1 ,3-dioxane; polyhexamethylenebiguanide or salts thereof; hexamethylenetetramine; methenamine 3-chloroallylochloride;2-chloroacetamide; chlorohexidine and its diglucononate, or diacetate esters and dihydrochloride salt thereof; 4,4-dimethyl, 1 ,3-oxazolidine; glutaraldehyde; 5- ethyl-3,7-dioxa-1 -azabicyclo octane; Sodium hydroxymethylglycinate, 3-lodo-2-propynyl butylcarbamate (IPBC) and ethyl lauroyl alginate. In certain embodiments, these components may be included in an amount of up to about 0.5% by weight of the end-use formulation.

[0135] In addition, the preservation agent may be a single preservation agent, a mixture of two or more preservation agents from a single type of preservation agent or may be a mixture of two or more different types of preservation agents.

[0136] Suitable preservation agents are phenolic compounds such as phenoxyethanol, bis (3-aminopropyl) dodecylamine, didecyl dimethyl ammonium chloride, sodium benzoate, lactic acid, benzyl alcohol, benzisothiazolinone, sorbic acid, and dehydroacetic acid, or a salt thereof.

[0137] The formulations and composition disclosed herein may further contain active ingredients, e.g. other antimicrobials, anti-inflammatories, plant extracts, bisabolol, panthenol, tocopherol, actives for antistinging, anti-irritant or anti-dandruff applications, or anti-aging agents such as retinol, melibiose and the like. Other suitable actives include e.g. Medicago officinalis, Actinidia chinensis, allantoin, Aloe barbadensis, Anona cherimolia, Anthemis nobilis, Arachis hypogaea, Arnica Montana, Avena sativa, beta-carotene, bisabolol, Borago officinalis, butylenes glycol, Calendula officinalis, Camellia sinensis, camphor, Candida bombicola, capryloyl glycine, Carica papaya, Centaurea cyanus, cetylpyridinium chloride, Chamomilla recutita, Chenopodium quinoa, Chinchona succirubra, Chondrus crispus, Citrus aurantium dulcis, Citrus grandis, Citrus limonum, Cocos nucifera, Coffea Arabica, Crataegus monogina, Cucumis melo, dichlorophenyl imidazoldioxolan, Enteromorpha compressa, Equisetum arvense, ethoxydiglycol, ethyl panthenol, farnesol, ferulic acid, Fragaria chiloensis, Gentiana lutea, Ginkgo biloba, glycerin, glyceryl laurate, Glycyrrhiza glabra, Hamamelis virginiana, heliotropine, hydrogenated palm glycerides, citrates, hydrolyzed castor oil, hydrolyzed wheat protein, Hypericum perforatum, Iris florentina, Juniperus communis, Lactis proteinum, lactose, Lawsonia inermis, linalool, Linum usitatissimum, lysine, magnesium aspartate, Magnifera indica, Malva sylvestris, mannitol, Melaleuca alternifolia, Mentha piperita, menthol, menthyl lactate, Mimosa tenuiflora, Nymphaea alba, olaflur, Oryza sativa, panthenol, paraffinum liquidum, PEG- 20M, PEG-26 jojoba acid, PEG-26 jojoba alcohol, PEG-35 castor oil, PEG-40 hydrogenated castor oil, PEG-60 hydrogenated castor oil, PEG-8 caprylic / capric acid, Persea gratissima, petrolatum, potassium aspartate, potassium sorbate, propylene glycol, Prunus amygdalus dulcis, Prunus armeniaca, Prunus persica, retinyl palmitate, Ricinus communis, Rosa canina, Rosmarinus officinalis, Rubus idaeus, salicylic acid, Sambucus nigra, sarcosine, Serenoa serrulata, Simmondsia chinensis, sodium carboxymethyl betaglucan, sodium cocoyl amino acids, sodium hyaluronate, sodium palmitoyl praline, stearoxytrimethylsilane, stearyl alcohol, sulfurized TEA-ricinoleate, talc, Thymus vulgaris, Tilia cordata, tocopherol, tocopheryl acetate, trideceth-9, triticum vulgare, tyrosine, undecylenoyl glycine, urea, Vaccinium my rtillus, valine, zinc oxide, zinc sulfate.

[0138] The person skilled in the art will appreciate that the end-use formulation may comprise the at least one antimicrobial compound according to the invention and additional ingredients that are classified as antimicrobial compound but also differently such as e.g. a skin care ingredient. In this connection, the end-use formulation may comprise the at least one antimicrobial compound (e.g. levulinic acid) and ascorbic acid (as skin care ingredient).

[0139] The antimicrobial composition of the present invention can be used in emulsions (both oil-in-water and water-in-oil), in aqueous solutions, in PIT (phase inversion temperature) emulsions, in oily solutions, in foaming cosmetic formulations (foams), and in so-called multiple emulsions, e.g. in triple emulsions (such as water / oil / water emulsions).

[0140] The antimicrobial composition of the present invention can also be formulated as creams, gels, liquids or lotions. They can be used in hair care products such as shampoos, hair conditioners, hair conditioning masks, hair styling products, hair dyes, hair tonic, hair gel, hair dressings, hair grooming aids and other hair care preparations; shaving applications such as shaving cream, aftershave lotions, and other shaving applications; personal cleaners for the body and hands, such as liquid bath soaps and detergents; fragrance preparations, such as perfumes, after bath splashes, and other similar fragrant preparations, skin care products, such as moisturizers, creams, and lotions and other similar skin care products, make-up products, such as colour cosmetic, mascara, base foundations and the like; make-up removal products, sun care products (e.g. sunscreen), indoor tanning products, toothpaste, mouthwash, and other similar personal care products. In certain embodiments, the antimicrobial composition disclosed herein may be incorporated in formulations used to saturate wipes, used for personal cleaning and hygiene (for example baby wipes, wet toilet wipes, make-up removal wipes and exfoliating wipes the like. The antimicrobial composition may also be used in other formulations where antimicrobial compounds are needed.

[0141] The above ingredients are in general also applicable to the home care products.

[0142] In certain embodiments, the antimicrobial composition may be incorporated into home care products, such as cleaning products e.g., hand-dish soaps, machine dish soaps, machine dish rinse-aids, laundry detergents, laundry fabric conditioners, clothing fragrance and / or wrinkle treatments, ironing aids, cleaning wipes, all-purpose cleaners and other similar formulations that are used around the home. In one embodiment, the home care product is a cleaning product selected from the group consisting of hand-dish soaps, laundry detergents, cleaning wipes, and cleaners, such as floor, work surface, kitchen, carpet, toilet and bathroom cleaners.

[0143] In certain embodiments, the antimicrobial composition may be included in wet wipe formulations that are used to saturate a wet wipe. In these embodiments, the antimicrobial composition may serve to preserve the wet wipe formulation and the wet wipe prior to use. Once the wet wipe composition is formulated, the wet wipe composition is applied to a substrate.

[0144] The wet wipe composition with the antimicrobial composition contained therein, may be applied to a substrate to be treated using conventional application techniques. Conventional techniques can include spraying, pouring, squirting and / or wiping the formulation on a substrate. In some embodiments, the wet wipe composition is provided to the end user as a ready-to-use formulation or is provided to the end user in a container with an application means. For example, the wet wipe composition may be provided in a container which is pressurized as an aerosol, a container with a trigger or pump sprayer, as a squirt container or conventional containers with a removable cap that allows the user to pour the formulation onto a substrate.

[0145] However, in certain embodiments, the wet wipe formulation containing the antimicrobial composition disclosed herein may be impregnated or applied to a wipe substrate. In this embodiment, the wipe is a single use wipe that is impregnated with the formulation and is stored in a container that will dispense the wipe to a user. The container with the wipes may contain a single wipe, or several wipes. Suitable containers include a pouch containing a single wipe, such as a moist towelette which is torn open by the user or may be a pouch with a resealable opening containing several wipes in a stacked fashion or other suitable formation that would allow a single wipe to be removed from the opening at a time. Pouches are generally prepared form a fluid impervious material, such as a film, a coated paper or foil or other similar fluid impervious materials. In certain embodiments, the wipe may be placed into a fluid impervious container having an opening to access the wipes in the container. In this manner, the user may remove one or more wipes from the opening in the container. Suitable containers can include molded plastic containers having lids that are generally fluid impervious. The lid may have an opening to access the wipes in the container. The wipes in the container may be situated in the container in an interleaved stacked, such that as a wipe is removed from the container the next wipe is positioned in the opening of the container ready for the user to remove the next wipe. Alternatively, in certain embodiments, the wipe may be a continuous material which is perforated between the individual wipes of the continuous material. The continuous wipe material with perforations may be in a folded form or may be in a rolled form. Generally, in the rolled form, the wipe material is fed from the centre of the rolled material and through the opening of the lid of the container for dispensing. As with the interleaved stack, as a wipe is removed from the container, the next wipe is positioned in the opening for the user to remove the next wipe, when needed.

[0146] Disposable wipes provide advantages over other application vehicles, such as a reusable sponge, rag or the like. Particularly advantageous is the fact that the impregnated wipe is used a single time and then disposed of, which is contrary to the use of sponges, rags and the like, which may be used repeatedly.

[0147] In some embodiments, the formulation containing the antimicrobial composition disclosed herein is impregnated into a wipe such that the wipe is pre-moistened and will express or release the formulation on to the substrate as the wipe is applied to the substrate to be treated. Generally, the formulation is saturated into the wipe such that the wipe will release the formulation to the substrate through wiping action.

[0148] Suitable wipe substrates include woven and nonwoven materials. In certain embodiments, any nonwoven web material may be used. Exemplary nonwoven materials may include, but are not limited to meltblown, coform, spunbond, airlaid, airlaced, hydroentangled nonwovens, spunlace, bonded carded webs, and laminates thereof. The fibers used to prepare the wipe substrate may be cellulosic fiber, thermoplastic fibers and mixtures thereof. The fibers may also be continuous fibers, discontinuous fibers, staple fibers and mixtures thereof. Basis weights of the nonwoven web may vary from about 12 grams per square meter to 200 grams per square meter (gsm) or more.

[0149] In one embodiment, the substrate impregnated with the wiping composition contains significant amounts of cellulosic fibers. In particular, the wiping composition of the present invention is particularly well suited for protecting the cellulose substrate from attack by microorganisms that can contaminate the product. In one particular embodiment, for instance, the substrate may be made from greater than 80%, such as greater than 85%, such as greater than 90%, such as greater than 95%, such as even 100% by weight cellulose fibers. For examples, in one embodiment, the substrate is made from pulp fibers and a binder in an airlaced process. The basis weight of the substrate can be from about 20 gsm to about 100 gsm, such as from about 40 gsm to about 70 gsm, such as from about 50 gsm to about 60 gsm.

[0150] Once incorporated into the substrate, the resulting wiping product can have a weight ratio of liquid to substrate of from about 5:1 to about 1 :1 , such as from about 2:1 to about 4:1 .

[0151] As aforementioned, the invention relates in a fourth aspect to a method for inhibiting microbial growth in a home care, a personal care product, or an aqueous raw material for addition into a home or personal care formulation comprising the step of adding the inventive antimicrobial composition to said home care or personal care product or aqueous raw material.

[0152] Embodiments e.g. regarding the respective antimicrobial composition and the home care or personal care product are already above-described and shall hold for the method, as well. Additional embodiments are described in the following.

[0153] Various different microorganisms may be controlled / in hibited in accordance with the present invention. For instance, the antimicrobial composition of the present invention can control gram positive bacteria, gram negative bacteria, and the like. In addition to bacteria, the antimicrobial composition of the present invention can also kill and control the growth of various other microorganisms, such as fungi, viruses, spores, yeast, mycobacteria, and the like. Non-limiting examples of particular microorganisms that may be controlled in accordance with the present invention include Staphylococcus aureus, Streptococcus pneumoniae, Pseudomonas aeruginosa, Serratia marcescens, Salmonella enteritidis, Neisseria gonorrhoeae, Escherichia coli, Enterococcus hirae, Acinetobacter baumannii, Listeria monocytogenes, Pluralibacter gergoviae, Enterobacter cloacae, Klebsiella pneumoniae, Burholderia cepacia, Pseudomonas putida, Kocuria rhizophila, Candida albicans, Saccharomyces cerevisiae, Aspergillus brasiliensis, Penicillium funiculosum, Penicillium chrysogenum, Eupenicillium levitum, Bacillus cereus, Bacillus subtilis, Clostridium difficile, Clostridium perfringens, Mycobacterium tuberculosis, Mycobacterium terrae, Mycobacterium avium, Poliovirus, Adenovirus, Norovirus, Vaccinia virus, Influenza virus, Hepatitis B virus, Human Immunodeficiency virus, Human papilloma virus, or mixtures thereof. The present invention further pertains in a fifth aspect to a method for preventing a home care or personal care product from spoilage by microorganisms, the method comprising adding the antimicrobial composition according to the present invention to the home care or personal care product.

[0154] The present invention further pertains in a sixth aspect to the use of the antimicrobial composition according to the present invention for increasing the efficacy against microorganisms compared to an equal amount of the at least one antimicrobial compound without said alkylene glycol ester.

[0155] The present invention further pertains to a seventh aspect to a method for increasing the efficacy of an antimicrobial compound against microorganisms in an end-use formulation, said method comprising providing an end-use formulation and at least one antimicrobial compound, adding an effective amount of an alkylene glycol ester to the least one antimicrobial compound and end-use formulation to increase the efficacy of the at least one antimicrobial compound in the end-use formulation, as compared to an equal amount of said antimicrobial compound without said alkylene glycol ester in the end-use formulation, wherein the at least one antimicrobial is selected from the group consisting of citric acid and salts thereof, salicylic acid and salts thereof, gluconolactone, levulinic acid and salts thereof, ethyl levulinate, butyl levulinate, ethylhexyl glycerin, ethylene glycol, 1 ,3-propanediol, 1 ,3-butanediol, 2,3-butanediol, 1 ,2-pentanediol, 1 ,2-hexanediol, caprylyl glycol, ethyl lactate, butyl lactate, climbazole, 1 ,2-decylene glycol, 4-hydroxyacetophenone, caprylhydroxamic acid and salts thereof, glyceryl caprylate, chlorphenesin, triclosan, methylheptylglycerin, polyglyeryl- 2 or 3 or 4 or 6 or 10 -caprylate, polyglyeryl- 2 or 3 or 4 or 6 or 10 -caprate / caprylate, azelaic acid, nonanoic acid, Vitamin C, zinc oxide, zinc citrate, zinc Pyrrolidone Carboxylic Acid (zinc PCA), zinc glycinate, zinc oxide, niacinamide, hyaluronic acid, 2-methyl-5- cyclohexylpentanol, Aluminium sulphate, Aluminium zirconium, Aluminum chloride, aluminium chlorhydrate, other aluminium salts, benzoyl peroxide, glycolic acid, phenethyl alcohol, 3- phenylpropan-1-ol, anisic acid and salts thereof, 1 ,2-heptanediol, caprylyl glyceryl ether, capryloyl glycine, tetrasodium glutamate diacetate, trisodium dicarboxymethyl alaninate, and phytic acid and salts thereof, and wherein said alkylene glycol ester is derived from (a) an alkylene glycol, and (b) a fatty acid having from about 6 to 14 carbon atoms.

[0156] Embodiments e.g. regarding the respective antimicrobial composition, the end-use formulation such as home care or personal care product, and the microorganisms are already above-described and shall hold for the fifth to seventh aspect, as well. Additional embodiments are described in the following.

[0157] In one embodiment, the increased efficacy is identified by a synergy index value of less than 1 .

[0158] It will be obvious for a person skilled in the art that the above embodiments only depict examples of a plurality of possibilities. Hence, the embodiments shown here should not be understood to form a limitation of these features and configurations. Any possible combination and configuration of the described features can be chosen according to the scope of the invention. All embodiments and preferred embodiments described herein in connection with one particular aspect of the invention (e.g. the inventive antimicrobial composition) shall likewise apply to all other aspects of the present inventions such as end-use formulations, uses or methods according to the present invention.

[0159] The following examples illustrate the invention without limitation. All parts and percentages provided are by weight unless otherwise indicated.

[0160] Examples

[0161] Methods

[0162] To demonstrate the synergistic effect in the examples below, the propylene glycol caprylate (PGC) used is a mixture of propylene glycol monocaprylates (octanoic acid-2-hydroxy-1 -methylethyl ester and 2-hydroxylpropyl caprylate) and propylene glycol dicaprylate (1 ,2-propylene glycol dicaprylate), the mixture comprising about 70-80 wt.-% of the propylene glycol monocaprylates and about 20-30 wt.-% of the propylene glycol dicaprylate.

[0163] Test procedure

[0164] The synergistic activity of Alkylene glycol esters and antimicrobial compounds are demonstrated as part of two-component compositions. A wide range of concentrations were tested against: Pseudomonas aeruginosa ATCC 9027 / DSM 1128, Staphylococcus aureus ATCC 6538 / DSM 799, Escherichia coll ATCC 8739 / DSM 1576, and Candida albicans ATCC 10231 / DSM 1386.

[0165] The lowest concentration of each mixture or single compound which prevents an observable level of growth was determined to be the minimum inhibitory concentration (MIC) value. The MIC value was determined for each microorganism.

[0166] Serial dilutions of each mixture or single compound were prepared. Micro-organisms were inoculated into media: Nutrient Broth (bacteria) or Malt Extract Broth (yeast). The final concentrations of micro-organisms in media was approximately 105CFU / ml. The inoculated media was introduced to each of the serial dilutions at a 1 :1 ratio, and incubated at 30±1 °C for 24-48 hours.

[0167] The MICs for each mixture was compared with the MIC of each single compound alone.

[0168] Synergy was determined using the Kull equation (F.C. Kull et. al., “Mixtures of Quaternary Ammonium Compounds and Long-chain Fatty Acids as Antifungal Agents”, Appl Microbiol. 1961 Nov; 9(6): 538-541), which calculates a Synergy Index (SI) according the following equation:

[0169] SI = Qa / QA + Qb / QB wherein

[0170] QA= concentration of compound A in ppm, acting alone produced an end point,

[0171] Qa = concentration of compound A in ppm, in the mixture, which produced an end point, QB = concentration of compound B in ppm, acting alone produced an end point, Qb = concentration of compound B in ppm, in the mixture, which produced an end point

[0172] In this study the end point is measured by the MIC. MIC’s have been rounded to the nearest whole number when appropriate.

[0173] Synergy is demonstrated by an SI value of less than 1 . An additive effect is demonstrated by an SI value of equal to 1 . Antagonism is demonstrated by an SI value of greater than 1 . Synergy index:

[0174] Synergistic interaction between Propylene glycol caprylate (PGC) and antimicrobial compounds.

[0175] Pseudomonas aeruginosa:

[0176] No MIC (minimum inhibitory concentration) was found for PGC therefore the MIC was assumed to be above the highest concentration tested. In these studies the MIC of PGC was determined to be above 50000 ppm and therefore 50000 ppm was used as the MIC. The below study used PEG 40 HCL to solubilise the hydroxyacetophenone. The MIC for PGC was determined for this assay independently.

[0177] Staphylococcus aureus:

[0178] The MIC for PGC was determined for each assay independently.

[0179] The below study used PEG 40 HCL to solubilise the 4-hydroxyacetophenone. The MIC for PGC was determined for this assay independently. Escherichia coli:

[0180] No MIC was found for PGC therefore the MIC was assumed to be above the highest concentration tested. In these studies the MIC of PGC was determined to be above 50000 ppm and therefore 50000 ppm was used as the MIC

[0181]

[0182]

[0183]

[0184]

[0185] Candida albicans: The MIC for PGC was determined for each assay independently.

[0186] The below study used PEG 40 HCL to solubilise the 4-hydroxyacetophenone. The MIC for PGC was determined for this assay independently.

Claims

Claims1. Antimicrobial composition comprising an alkylene glycol ester and at least one antimicrobial compound selected from the group consisting of citric acid and salts thereof, salicylic acid and salts thereof, gluconolactone, levulinic acid and salts thereof, ethyl levulinate, butyl levulinate, ethylhexyl glycerin, ethylene glycol, 1 ,3-propanediol, 1 ,3-butanediol, 2,3-butanediol, 1 ,2-pentanediol, 1 ,2- hexanediol, caprylyl glycol, ethyl lactate, butyl lactate, climbazole, 1 ,2-decylene glycol, 4- hydroxyacetophenone, caprylhydroxamic acid and salts thereof, glyceryl caprylate, chlorphenesin, triclosan, methylheptylglycerin, polyglyceryl- 2 or 3 or 4 or 6 or 10 -caprylate, polyglyceryl- 2 or 3 or 4 or 6 or 10 -caprate / caprylate, azelaic acid, Vitamin C, zinc oxide, zinc citrate, zinc pyrrolidone carboxylic Acid (zinc PCA), zinc glycinate, zinc oxide, niacinamide, hyaluronic acid, 2-methyl-5- cyclohexylpentanol, Aluminium sulphate, Aluminium zirconium, Aluminum chloride, aluminium chlorhydrate, other aluminium salts, benzoyl peroxide, Glycolic acid, phenethyl alcohol, 3- phenylpropan-1-ol, anisic acid and salts thereof, 1 ,2-heptanediol, caprylyl glyceryl ether, capryloyl glycine, tetrasodium glutamate diacetate, trisodium dicarboxymethyl alaninate, and phytic acid and salts thereof, wherein said alkylene glycol ester and said antimicrobial compound are present in a weight ratio of about 1 :1000 to about 2500:1 .

2. Antimicrobial composition comprising an alkylene glycol ester and at least one antimicrobial compound selected from the group consisting of citric acid and salts thereof, salicylic acid and salts thereof, gluconolactone, levulinic acid and salts thereof, ethyl levulinate, butyl levulinate, ethylhexyl glycerin, ethylene glycol, 1 ,3-propanediol, 1 ,3-butanediol, 2,3-butanediol, 1 ,2-pentanediol, 1 ,2- hexanediol, caprylyl glycol, ethyl lactate, butyl lactate, climbazole, 1 ,2-decylene glycol, 4- hydroxyacetophenone, caprylhydroxamic acid and salts thereof, glyceryl caprylate, chlorphenesin, triclosan, methylheptylglycerin, polyglyeryl- 2 or 3 or 4 or 6 or 10 -caprylate, polyglyeryl- 2 or 3 or 4 or 6 or 10 -caprate / caprylate, azelaic acid, Vitamin C, zinc oxide, zinc citrate, zinc Pyrrolidone Carboxylic Acid (zinc PCA), zinc glycinate, zinc oxide, niacinamide, hyaluronic acid, 2-methyl-5- cyclohexylpentanol, Aluminium sulphate, Aluminium zirconium, Aluminum chloride, aluminium chlorhydrate, other aluminium salts, benzoyl peroxide, glycolic acid, phenethyl alcohol, 3- phenylpropan-1-ol, anisic acid and salts thereof, 1 ,2-heptanediol, caprylyl glyceryl ether, capryloyl glycine, tetrasodium glutamate diacetate, trisodium dicarboxymethyl alaninate, and phytic acid and salts thereof, wherein said alkylene glycol ester and said antimicrobial compound are present in a synergistically effective amount.

3. The antimicrobial composition according to claim 1 or 2, wherein said alkylene glycol ester comprises propylene glycol ester, preferably propylene glycol caprylate, and in particular propylene glycol monocaprylate.

4. The antimicrobial composition according to and one of claims 1 to 3, wherein said alkylene glycol ester is selected from the group consisting of alkylene glycol monoester, alkylene glycol diester, and mixtures thereof, preferably selected from the group consisting of propylene glycol monoester, propylene glycol diester, and mixtures thereof, more preferably selected from the group consisting of propylene glycol monocaprylate, propylene glycol dicaprylate, and mixtures thereof, and in particular a mixture of propylene glycol monocaprylate and propylene glycol dicaprylate or propylene glycol monocaprylate.

5. The antimicrobial composition according to any one of claims 1 to 4, wherein said alkylene glycol ester is a mixture of propylene glycol monocaprylate and propylene glycol dicaprylate comprising at least 10 wt.-%, preferably at least 30 wt.-%, and in particular at least 60 wt.-%, of the propylene glycol monocaprylate, based on the weight sum of propylene glycol monocaprylate and propylene glycol dicaprylate.

6. The antimicrobial composition according to any one of claims 1 to 5, wherein said alkylene glycol ester and said antimicrobial compound are present in a weight ratio of about 1 :1000 to about 2000:1 , or about 1 :1000 to about 1500:1 , or about 1 :1000 to about 500:1 , or about 1 :1000 to about 50:1 , or about 1 :800 to about 200:1 , or about 1 :800 to about 40:1 , or about 1 :600 to about 1 :150, or about 1 :600 to about 30:1 , or about 1 :550 to about 100:1 , or about 1 :550 to about 20:1 .

7. The antimicrobial composition according to any one of claims 1 to 6, wherein the least one antimicrobial compound is selected from the group consisting of citric acid and salts thereof, salicylic acid and salts thereof, gluconolactone, levulinic acid and salts thereof, ethyl levulinate, butyl levulinate, ethylhexyl glycerin, ethylene glycol, 1 ,3-propanediol, 1 ,3-butanediol, 2,3-butanediol, 1 ,2-pentanediol, 1 ,2-hexanediol, caprylyl glycol, ethyl lactate, methylheptylglycerin, zinc glycinate, and butyl lactate, preferably levulinic acid.

8. The antimicrobial composition according to claim 1 or 2, wherein said alkylene glycol ester is propylene glycol caprylate (PGC) and said antimicrobial compound is citric acid, and wherein said PGC and said citric acid are present in a weight ratio of about 1 :32 to about 200:1 .

9. The antimicrobial composition according to claim 1 or 2, wherein said alkylene glycol ester is propylene glycol caprylate (PGC) and said antimicrobial compound is sodium salicylate, andwherein said PGC and said sodium salicylate are present in a weight ratio of about 1 :128 to about 20:1.

10. The antimicrobial composition according to claim 1 or 2, wherein said alkylene glycol ester is propylene glycol caprylate (PGC) and said antimicrobial compound is gluconolactone, and wherein said PGC and said gluconolactone are present in a weight ratio of about 1 :128 to about 80:1.11 . The antimicrobial composition according to claim 1 or 2, wherein said alkylene glycol ester is propylene glycol caprylate (PGC) and said antimicrobial compound is levulinic acid, ethyl levulinate, or butyl levulinate, and wherein said PGC and said levulinic acid, ethyl levulinate, or butyl levulinate are present in a weight ratio of about 1 :256 to about 5:1 , preferably wherein said antimicrobial compound is levulinic acid, and wherein said PGC and said levulinic acid are present in a weight ratio of about 1 :256 to about 5:1 or wherein said antimicrobial compound is ethyl levulinate or butyl levulinate, and wherein said PGC and said ethyl levulinate or butyl levulinate are present in a weight ratio of about 1 :256 to about 1 :1 .

12. The antimicrobial composition according to claim 1 or 2, wherein said alkylene glycol ester is propylene glycol caprylate (PGC) and said antimicrobial compound is ethylhexyl glycerin, and wherein said PGC and said ethylhexyl glycerin are present in a weight ratio of about 1 :32 to about 4:1.

13. The antimicrobial composition according to claim 1 or 2, wherein said alkylene glycol ester is propylene glycol caprylate (PGC) and said antimicrobial compound is caprylyl glycol, 1 ,2- pentanediol, or 1 ,2-hexanediol, and wherein said PGC and said caprylyl glycol, 1 ,2-pentanediol, or 1 ,2-hexanediol are present in a weight ratio of about 1 :256 to about 5:1 , preferably wherein said antimicrobial compound is caprylyl glycol, and wherein said PGC and said caprylyl glycol are present in a weight ratio of about 1 :8 to about 5:1 , or wherein said antimicrobial compound is 1 ,2- pentanediol, and wherein said PGC and said 1 ,2-pentanediol are present in a weight ratio of about 1 :256 to about 2:13, or wherein said antimicrobial compound is 1 ,2-hexanediol, and wherein said PGC and said 1 ,2-hexanediol are present in a weight ratio of about 1 :128 to about 4:13 and / or wherein said alkylene glycol ester is propylene glycol caprylate (PGC) and said antimicrobial compound is ethylene glycol, 1 ,3-propanediol, 1 ,3-butanediol or 2,3 butanediol and wherein said PGC and said ethylene glycol, 1 ,3-propanediol, 1 ,3-butanediol or 2,3 butanediol are present in a weight ratio of about 1 :256 to about 10:1 , preferably wherein said antimicrobial compound is ethylene glycol, and wherein said PGC and said ethylene glycol are present in a weight ratio of about 1 :256 to about 10:1 , or wherein said antimicrobial compound is 1 ,3-propanediol, and whereinsaid PGC and said 1 ,3-propanediol are present in a weight ratio of about 1 :128 to about 5:1 , or wherein said antimicrobial compound is 1 ,3-butanediol, and wherein said PGC and said 1 ,3- butanediol are present in a weight ratio of about 1 :128, or wherein said antimicrobial compound is 2,3-butanediol, and wherein said PGC and said 2,3-butanediol are present in a weight ratio of about 1 :128.

14. The antimicrobial composition according to claim 1 or 2, wherein said alkylene glycol ester is propylene glycol caprylate (PGC) and said antimicrobial compound is ethyl lactate or butyl lactate, and wherein said PGC and said ethyl lactate or butyl lactate are present in a weight ratio of about 1 :512 to about 1 :1 , preferably wherein said antimicrobial compound is ethyl lactate, and wherein said PGC and said ethyl lactate are present in a weight ratio of about 1 :512 to about 1 :1 or wherein said antimicrobial compound is butyl lactate, and wherein said PGC and said butyl lactate are present in a weight ratio of about 1 :128 to about 1 :1.

15. The antimicrobial composition according to claim 1 or 2, wherein said alkylene glycol ester is propylene glycol caprylate (PGC) and said antimicrobial compound is nonanoic acid, and wherein said PGC and said nonanoic acid are present in a weight ratio of about 1.1 to 8:1 .

16. The antimicrobial composition according to claim 1 or 2, wherein said alkylene glycol ester is propylene glycol caprylate (PGC) and said antimicrobial compound is 4-hydroxyacetophenone, and wherein said PGC and said 4-hydroxyacetophenone are present in a weight ratio of about 8:1 to 1 :8.

17. An end-use formulation, preferably a home care or personal care product, comprising an antimicrobial composition according to any one of claims 1 to 16.

18. The home care or personal care product according to claim 17, wherein the antimicrobial composition has a weight of 0.02 to 10% based on the total weight of the home care or personal care product, and / or wherein said antimicrobial composition is the antimicrobial composition according to claim 11 , preferably wherein said antimicrobial compound is levulinic acid.

19. The personal care product according to claim 17 or 18, which is selected from the group consisting of shampoo, skin lotion, shower gel, deodorant, bubble bath, bath oil, cream, baby product, liquid soap, hair gel, hair conditioner, hair conditioning mask, hair styling product, make-up, sunscreen, colour cosmetic, toothpaste, mouthwash and wet wipe.

20. The home care product according to claim 17 or 18, which is a cleaning product, preferably selected from the group consisting of hand-dish soaps, machine dish soaps, machine dish rinse-aids, laundry detergents, laundry fabric conditioners, clothing fragrance and / or wrinkle treatments, ironing aids, cleaning wipes, and all-purpose cleaners.21 . A method for inhibiting microbial growth in a home care, a personal care product, or an aqueous raw material for addition into a home care or personal care product comprising the step of adding the antimicrobial composition according to any one of the claims 1 to 16 to said home care or personal care product or aqueous raw material.

22. A method for preventing an end-use formulation, preferably a home care or personal care product, from spoilage by microorganisms, the method comprising adding the antimicrobial composition according to any one of claims 1 to 16 to the end-use formulation, preferably the home care or personal care product.

23. Use of the antimicrobial composition according to any one of claims 1 to 16 for increasing the efficacy against microorganisms compared to an equal amount of the at least one antimicrobial compound without said alkylene glycol ester, preferably wherein the increased efficacy is identified by a synergy index value of less than 1 .

24. A method for increasing the efficacy of an antimicrobial compound against microorganisms in an end-use formulation, said method comprising providing an end-use formulation and at least one antimicrobial compound, adding an effective amount of an alkylene glycol ester to the least one antimicrobial compound and end-use formulation to increase the efficacy of the at least one antimicrobial compound in the end-use formulation, as compared to an equal amount of said antimicrobial compound without said alkylene glycol ester in the end-use formulation, wherein the at least one antimicrobial is selected from the group consisting of citric acid and salts thereof, salicylic acid and salts thereof, gluconolactone, levulinic acid and salts thereof, ethyl levulinate, butyl levulinate, ethylhexyl glycerin, ethylene glycol, 1 ,3-propanediol, 1 ,3-butanediol, 1 ,2-pentanediol,1 ,2-hexanediol, caprylyl glycol, ethyl lactate, butyl lactate, climbazole, 1 ,2-decylene glycol, 4- hydroxyacetophenone, caprylhydroxamic acid and salts thereof, glyceryl caprylate, chlorphenesin, triclosan, methylheptylglycerin, polyglyeryl- 2 or 3 or 4 or 6 or 10 -caprylate, polyglyeryl- 2 or 3 or 4 or 6 or 10 -caprate / caprylate, azelaic acid, nonanoic acid, Vitamin C, zinc oxide, zinc citrate, zinc Pyrrolidone Carboxylic Acid (zinc PCA), zinc glycinate, zinc oxide, niacinamide, hyaluronic acid, 2- methyl-5-cyclohexylpentanol, Aluminium sulphate, Aluminium zirconium, Aluminum chloride, aluminium chlorhydrate, other aluminium salts, benzoyl peroxide, glycolic acid, phenethyl alcohol, 3- phenylpropan-1-ol, anisic acid and salts thereof, 1 ,2-heptanediol, caprylyl glyceryl ether, capryloyl glycine, tetrasodium glutamate diacetate, trisodium dicarboxymethyl alaninate, and phytic acid andsalts thereof and wherein said alkylene glycol ester is derived from (a) an alkylene glycol, and (b) a fatty acid having from about 6 to 14 carbon atoms.

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